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JANUARY 1974

THE

NAUTILUS

Vol. 88
No. 1

A quarterly

devoted to

malacology and

the interests of

conchologists

Founded 1 889 by Henry A. Pilsbry. Continued by H. Burrington Baker.
Editors: R. Tucker Abbott and Charles B. Wurtz

EDITORIAL COMMITTEE

CONSULTING EDITORS

Dr. Arthur H. Clarke, Jr.
Department of Mollusks
National Museum of Canada
Ottawa, Ontario, Canada KIA-0M8

Dr. WUliam J. Clench
Curator Emeritus
Museum of Comparative Zoology
Cambridge, Mass. 02138

Dr. William K. Emerson

Department of Living Invertebrates

The American Museum of Natural History

New York, New York 10024

Mr. Morris K. Jacobson

Department of Living Invertebrates

The American Museum of Natural History

New York, New York 10024

Dr. Aurele La Rocque
Department of Geology
The Ohio State University
Columbus, Ohio 43210

Dr. James H. McLean

Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, California 90007

Dr. Arthur S. Merrill
Biological Laboratory
National Marine Fisheries Service
Oxford, Maryland 21654

Dr. Donald R. Moore

Division of Marine Geology

School of Marine and Atmospheric Science

10 Rickenbacker Causeway

Miami, Florida 33149

Dr. Joseph Rosewater
Division of Mollusks
U. S. National Museum
Washington, D.C. 20560

Dr. G. Alan Solem

Department of Invertebrates
Field Museum of Natural History
Chicago, Illinois 60605

Dr. David H. Stansbery
Museum of Zoology
The Ohio State University
Columbus, Ohio 43210

Dr. Ruth D. Turner

Department of Mollusks
Museum of Comparative Zoology
Cambridge, Mass. 02138

Dr. Gilbert L. Voss
Division of Biology

School of Marine and Atmospheric Science
1 0 Rickenbacker Causeway
Miami, Florida 33149

EDITORS

Dr. R. Tucker Abbott

Delaware Museum of Natural History
Box 3937, Greenville, Delaware 19807

Dr. Charles B. Wurtz
3220 Penn Street
Philadelphia, Pennsylvania 19129

Mrs. Horace B. Baker

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1 1 Chelten Road

Havertown, Pennsylvania 19083

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THE
NAUTILUS

Volume 88, number 1 — January 1974

CONTENTS

Kenneth D. Rose

The Rehgious Use of Turbinella pyrum (Linnaeus), the Indian Chank 1

Lowell L. Getz

Species Diversity of Terrestrial Snails in the Great Smoky Mountains 6

Hal Lewis

A New Species of Hawaiian Gyrineum (Cymatiidae) 10

Richard Houbrick

Growth Studies on the Genus Cerithium (Gastropoda: Prosobranchia)

with Notes on Ecology and Microhabitats 14

Morris K. Jacobson and William E. Old, Jr.

On a Sinistral Specimen oiLiguus virgineus (with Additional Remarks

on the Genus Liguus) ^°

Edward M. Stern

The Chromosome Number of Euglandina rosea (Stylommatophora: Oleacinidae) 29

Book Reviews

(of) American Malacologists, 27; A. Gordon Melvin, 30; Publications Received ii

INDEX TO THE NAUTILUS

An index to The Nautilus, both author volume 90 in early 1977. It will cover

and subject matter, will appear every five volumes 86 through 90 (1972-76). An

years. The first index to cover the new format accumulative index is tentatively planned in

will be issued separately at the completion of 1986 to cover volumes 61 through 100.

STATEMENT OF OWNERSHIP, MANAGEMENT AND
CIRCULATION (Required by) Act of October 23, 1962:
Section 4396. Title 39. United States Code, and postal
regulation 132-622.

1. Title of publication: THE NAUTILUS.

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Museum of Natural History, Kennett Pike, Box 3937,
Greenville, De. 19807.

5. Location of the Headquarters or General Business
Offices of the Publishers: Delaware Museum of Natural
History, Kennett Pike, Box 3937, Greenville, De. 19807.

6. Names and addresses of publisher, editor, and managing
editor: Publisher, Mrs. Horace Burrington Baker, 11
Chelten Rd., Havertown, Pa. 19083. Editor, R. Tucker
Abbott, Delaware Museum of Natural History, Box
3937, Greenville, De. 19807. Managing editor, none.

7. Owner: Mrs. Horace Burrington Baker, 11 Chelten Rd.,
Havertown, Pa. 19803.

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holders owning or holding 1 percent or more of total
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RECENT PUBLICATIONS

Boss, K. J. and M. K. Jacobson. 1973. Monograph of
Ceratodiscus (Archaeogastropoda; Helicinidae).
Occasional Papers on Mollusks, Harvard Univ., vol.
3, no. 45, pp. 253-279, 4 pis. Three species of this
operculate land snail from tlie Greater Antilles are
well treated. $1.40.

Boss, K. J. and M. K. Jacobson. Sept. 1973.
Monograph of the Genus Alcadia in Cuba
(Mollusca: Prosobranchia: Helicinidae). Bull. Mus.
Comp. Zool., Harvard, vol. 145, no. 7, pp.
311-358, 6 pis. The genus is fully treated, with a
new subgenus Glyptalcadia and a new subspecies,
A. bermudezi jatibonica from Las VUlas, Cuba.

Johnson, Richard I. 1973. Distribution of Hydro-
biidae, A Family of Fresh and Brackish Water
Gastropods, in Peninsular Florida. Occ. Papers on
Moll., Harvard Univ., vol. 3, no. 46, pp. 281-303.
The late Tertiary topographical history of Florida
is interpreted from present-day hydrobiid
mollusks, refuting some of F. G. Thompson's 1968
interpretations. $1.20.

Stem, Edward M. 1973. The Ashmunella rhyssa
(Dall) Complex (Gastropoda: Polygyridae): Sierra
Blanca — Sacramento Mountains, New Mexico.
Science Series No. 5, Univ. of Texas at El Paso, VII
& 57 pp., 18 text figs., 1 pi. $2.00.

Ruhoff, Florence A. 1973. BibUography and
Zoological Taxa of Paul Bartsch [1871-1960],
with a Biographical Sketch by Harald A. Rehder.
Smithsonian Contributions to Zoology, no. 143,
pp. V + 166. Excellently done and extremely
useful. $2.85 postpaid, Smitlisonian Institution
Press, Wash. D. C.

Kaicher, Sally D. Oct. 1973. Card Catalogue of
World-wide Shells. MargineUidae, pack no. 1, 97
cards. A useful and novel set of 3x5-inch cards,
each bearing good black-and-white photographs,
identification, marine province and short notes on
colors and habitats. $3.00 per pack (postpaid),
foreign $4.00 (airmail postpaid). Sally D. Kaicher,
5633B 18th Way South, St. Petersburg, Ra.
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indispensable ix

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Vol. 88(1)

THE NAUTILUS

THE RELIGIOUS USE OF Ti RHINE LLA PYRUM (LINNAEUS),
THE INDIAN CHANK

Kenneth D. Rose

Museum of Comparative Zoology, Harvard University
Cambridge, Massachusetts 02138

ABSTRACT

The Indian chank, Turbinella pyrum (Linnaeus), has played an important role in
Indian religion and art for centuries. Hundreds of years before the birth of Christ,
chanks were in use in the Indus Valley civilizations. Chank sections and bangles
served as ornaments and jewelry in many parts of India in the early Christian era.
The earliest utilization of chanks as amulets and religious objects dates back nearly
two millenia. Sinistral ("left-handed") specimens are very rare and have received the
greatest veneration. Various Hindu gods have been associated with the chank; the
most prominent of these is unquestionably Vishnu (or his incarnation Krishna), who
is so often affdiated with the chank that it has become a reliable symbol of him.
References to chanks, especially those modified as trumpets, are numerous in Hindu
legends, and sacred wcitings such as the Bhagavad Gita. Some authors have suggested
that Hindu influence may be responsible for similar reverence of large gastropod
shells by the Aztecs.

It is well-known that shellfish and seashells have
long been significant items to the peoples of the
Indian subcontinent. The early Hindus grouped
crabs and mollusks under the name kambustha and
used the cleaned shells as ornaments and amulets.
Some shells, such as cowries, have served as
money in parts of India (as well as throughout the
Indo-Pacific region) for centuries in the past. Such
uses as these have occurred in many cultures and
have not necessarily been restricted to one or a
few species.

The Indian chank, Turbinella pyrum (Linnaeus)
1758, is an example of an unusual instance in
which one molluscan species has acquired a very
special religious significance. The chank attained its
prominence as a symbol of the Hindu god Vishnu,
who is often portrayed holding a sinistral chank in
one of his four hands. It is recognized particulariy
as an emblem of Krishna, the most important
avatar of Vishnu; but the chank is sometimes
associated with other Hindu gods. The basis for
the chank's religious significance can be traced to
many Hindu legends, as will be shown below.
Some preliminary remarks on the classification.

FIG. 1. Map of the Indian subcontinent

THE NAUTILUS

January 29. 1974

Vol. 88(1)

natural history, and ornamental uses of the species
will be discussed first.

The controversy over the proper nomenciature
for the Indian chank has been reviewed recently

(Yokes, 1964) and is summarized here. Tiie chank
was first named by Linnaeus (1758). who coined
the binomial Valuta pynim for the species.
Lightfoot (1786) listed the name Vohiia ponderosa
for a sinistral ("left-handed") specimen of the
Indian chank. but the name is unnecessary and
invalid, for it refers to the same species described
by Linnaeus. Later students discovered that this
species had been incorrectly placed in the genus
\'<>luia. Tiic genus name Xancus first appeared in
reference to the Indian chank in Roding's Bolten
Museum Catalogue (1798). but this reference was
rather obscure until the eariy part of ihc twen-
tieth century. TJierefore. Lamarck's (1799) name
Turhinclla became widely known and was applied
to the Indian chank by most authorities (e.g.
Horneli. 1916) for more than a century. More
recently, the name Xancus returned to use. due to
a ruling on priority by the International Commis-
sion on Zoological Nomenclature (Opinion 96,
1926); but a later Opinion of the Commission
(Opinion 489, 1957) reversed the 1926 ruling,
formally suppressing the name Xancus and requir-
ing use of the name Turbinella. Turbinclla pyrum
is a member of the family Vasidae.

Turbinclla pyntm occurs commonly in the Bay
of Bengal off the Indian coast and in the vicinity
t)f the Andaman Islands, and in the waters
surrounding Ceylon, particularly the Gulf of Man-
nar (Horneli. 1913, 1916. 1951). The Andaman
islands form is often regarded as a distinct
subspecies. Turbinclla pyrum fusus Sowerby 1825;
it is characterized by its higli spire and angular
shoulder. Other subspecies have been described
(see, for example. Horneli. 1916) but most of
these have not achieved universal acceptance. Like
the majority of gastropods, the shell of Turbinella

FIG. 2. A rare sinistral specimen (MCZ no.
249020) of the Sacred Indian Chank, Turbinella
pyrum (Linnaeus) (= "Voluta ponderosa" Light-
foot, no. 402.-I in the Portland Catalogue). This
prized specimen, once in the collection of the
Duchess of Portland, is from the Trincomali Coast
of India. It was purchased for the Museum of
Comparative Zoology about fifteen years ago, as
part of the collection of Mrs. Fiske Warren. (Scale
is in centimeters.)

Vol. 88(1)

THE NAUTILUS

pynim is typically dextral ("right-handed") but, as
noted above, rare sinistral specimens have been
recorded. It is the latter that have achieved the
higliest veneration.

The cleaned shell of the Indian chank is heavy
and porcelainlike, a factor which contributes to its
popularity and utility in jewelry and ornamental
work. It is usually white or cream-colored, or
rarely pnikish. in life, the shell is covered with a
thick, light-brown periostracum, which may func-
tion to some degree to protect the shell from
boring sponges. Tlie animals are gregarious and are
frequently found in large numbers on sand in
relatively shallow water, up to ten fathoms deep.
They feed chiefly on tube worms (Hornell, 1951).
An interesting account of the breeding and larval
development of Turbinella pynim is presented by
Hornell (1951, pp. 24-25).

Tlie use of the chank as an ornamental or
religious object, although prevalent today, was
perhaps more popular in the past. Bangles cut
from the shell were widespread in India in ancient
times, and have been the center of a small
industry in more recent times. Chanks have been
found in the excavations of the Indus Valley
civilizations, which date back to centuries before
the birth of Christ. They may have been collected
from the Persian Gulf at that time. Chank sections
were used in inlay patterns (e.g., petals, rosettes,
crosses) in northwestern India over two thousand
years ago, but examples are quite rare (Agrawala,
1965).

Important bangle workshops were located from
Tinnevelly in the south to Kathiawar and Gujarat
in the northwest, during the reign of the Pandyan
kings in the early Christian era. "Maduraikkanchi",
a Tamil poem of the second or third century A.
D., describes the parawas, men who dived for
pead oysters and chanks. In fact, the parawas are
still active today (N. Hein, personal communica-
tion). Another Tamil poem, attributed to the reign
of the Pandyan King Nadunj Cheliyan II (second
century A. D. ?), mentions sectioning chanks for
use as bangles (Hornell, 1913).

In north-central India, as eady as the first or
second century A. D., there is evidence indicating
that the religious significance of the chank was
already established. Terracotta seals from Rajghat,
near Benares, associate Vishnu with religious
emblems including the wheel, spear and chank.

The chank again appears in slightly later seals and
seal impressions from the early Gupta Period
(fourth century A. D.) at Basarh and Rajgliat.
Inscriptions on some seals from Basarh and Bhita
reveal associations of the chank with the god Siva
and the goddess Laksmi, consort of Vishnu
(Banerjea, 1941). Chanks also were "extensively
used in wars by ancient Indians" (Bhattacharyya,
1958, p. 438), supposedly to inspire warriors and
to frigliten away the enemy. Indeed, the venera-
tion of the chank by Hindus has evolved in large
part from legends of its use as a war trumpet by
the god Krishna.

In more recent times, chank fisheries in India
and Ceylon have gathered as many as two or three
million chank shells per annum. Additional sub-
recent shells are excavated from the silt beds of
the Jaffna Lagoons in Ceylon. Chanks have been
sent to Calcutta and Dacca to be sectioned for use
as bangles by Hindu women of all castes. In this
century, chank bangles have been most popular in
Bengal and surrounding states (Hornell, 1913,
1951). Not very long ago, the chank apparently

FIG. 3. A normal (dextral) specimen of Turbinella
pyrum (MCZ no. 235923). (Scale is in centi-
meters. }

THE NAUTILUS

January 29. 1974

Vol. 88 ( 1 )

achieved status as a good-luck charm in the Tamil
districts of Madras. Whole shells and circular,
hollowed sections worn as bracelets were used as
amulets by some people, to (in the words of
Homell, 1913, p. 410) "protect them against the
baneful influence of the evil eye." Hornell (mi3)
also reported their use as ornaments on the
forehead of drauglit bulls in southern India. As
religious objects chunks, which may be modified as
trumpets, are often seen in Hindu temples; and
they have been used in recent times in place of
bells to initiate worship of the god Siva (N.
Hein, personal communication).

Chanks, especially sinistral specimens, have been
of importance not only to Hindus, but also to
Buddliists. According to Homell (1951), sinistral
shells have been mounted in silver in some Tibetan
lamaseries; and the value of "left-handed" chanks
was once considered to be their weight in gold.
Tlie chank has been associated with the Buddhist
deities Sagaramati and Gandlialiasli (Bhattacharyya,
1958).

In the Hindu pantheon, Vishnu (or his incarna-
tion Krishna) is the deity most often atfiliated
with the chank - so often, in fact, that the chank
has become a reliable symbol of Vishnu. Other
Hindu gods, however, are occasionally shown in
connection with a chank. For example, Siva is
sometimes depicted with a chank in his hand
(Jackson, 1916); Kubera, the corpulent god of
wealth, may be portrayed with his foot resting on
a chank (Rubel, 1968).

The association of the chank with Krishna
derives from the sacred Hindu poem Bhagavad
Gita ("The Song of the Blessed One"), which
forms a part of the great Hindu epic Mahabharata,
Although the Bhagavad Gita was evidently not
included in the original epic, and may have been
written at a later date (Edgerton, 1964), it has for
centuries been considered an integral part of the
Mahabharata; it is unquestionably one of the most
highly regarded of all Hindu sacred scriptures. The
Bhagavad Gita itself is a dialogue (between Krishna
and Arjuna, a warrior) in which major Hindu
doctrines are expounded; while the main theme of
the entire Mahabharata concerns a battle. Frequent
references to the impending battle appear through-
out the Bhagavad Gita, and it is in these that the
chank is of paramount importance. The Sanskrit
term sahkha, usually translated simply as "conch",

is almost certainly a reference to the Indian
chank.

In Chapter 1 of the Bhagavad Gita, each warrior
preparing for battle can be recognized by his
personal conch, which is distinctive in color, size,
and sound (Walker, 1968). In Chapter I, verse 12
(Edgerton, 1964, 1:12), we read "The aged
grandsire of the Kurus . . . blew his conch-shell,
in full valor." Conch trumpets were sounded
before the battle, and Arjuna and Krishna blew
their conchs (Edgerton, 1:13-14). King Yudhisthira
blew liis conch, named Anatavijaya: it was a long,
slender yellow shell, with a mellow tone. Nakula's
conch. Siighosa, was large, heavy, and gray, and it
produced a neigliing sound. Sahadeva possessed a
long, slender, pink chank called Manipuspaka
("little jewel-flower"), which emitted a mooing
sound (Edgerton, 1:16). Arjuna's chank was named
Devadatta, "god-given" (Edgerton, 1:15). Tlie most
important conch of all belonged to Krishna. It was
a small, slender, sweet-sounding shell, called
Panchajanya (Walker, 1968).

According to legend, Krishna obtained his
sacred shell in a confrontation with the demon
Panchajana. In one version of the myth (Munshi,
1963-1965) Panchajana, an evil member of a
seagoing tribe, wore a beautiful pink conch over
his shoulder. Krishna noticed the demon's shell
and remarked " i will take this conch. I have
never seen such a thing of beauty, nor heard such
wonderful tones. I shall call it Panchajanya, the
gift of Panchajana' " (Munshi. 2, p. 60). In another
interpretation of the same legend (Walker, 1968),
Panchajana lived in a shell at the bottom of the
sea. Krishna pursued the demon and slew him, and
used his shell for a trumpet.

A different legend describes tlie chank as one
of fourteen jewels (chaturdasa-ratnam) which e-
merged Uom the "churning of the ocean", a major
event in the epic confrontation between the gods
and the demons. The chank was taken by Vishnu,
but it was soon stolen from him by the shell
demon, Sankasura. Vishnu slew the demon, how-
ever, and recovered the conch, dedicating it to his
own service. Thus chanks are blown in temple
worship in modern time (Walker, 1968).

Numerous other allusions to chanks in Hindu
lore clearly associate them with Krishna. In the
Krishnavatara, Krishna blew his chank trumpet to
challenge the Rakshasa demons to battle; but the

Vol. 88(1)

THE NAUTILUS

sound served to summon his friends, while scaring
the demons to flight (Munshi, 3 pp. 189-200).
Another tale relates Krishna's meeting with the
King of Karavirapura. The deity arrived in a
chariot, blowing his chank trumpet to greet the
king (Munshi, 2, pp. 175-182). The Leelas of
Krishna, stories adapted from the Bhagavata Para-
na, tell of a wrestling match, between Krishna and
a demon, which is initiated by trumpet blasts,
perhaps chank trumpets, in a later episode, the
arrival of Krishna at the court of his intended
bride is accompanied by a flourish of trumpets
(Sarma, 1948); this passage, too, probably refers
to the chank.

It may be significant that in the Aztec
culture, similar reverence was centered around
large snail shells, including Turbinella angulata
(Lightfoot, 1786), a close relative of the Indian
chank (Jackson, 1961; Yokes, 1963). Jackson
emphasized similarities between Indian mythology
involving the chank and Aztec moon worship
involving large snail shells. Hindu influence on
early Middle American civilizations is considered a
distinct possibility by these authors.

ACKNOWLEGDMENTS

I am grateful to Dr. Norvin Hein, Department
of ReUgjous Studies, Yale University, who read an
earlier draft of this paper and offered helpful
comments. I am indebted also to Dr. R. Tucker
Abbott for providing suggestions regarding the
text, and for calling my attention to several
pertinent references. Dr. Kenneth Boss, Depart-
ment of Mollusks, Museum of Comparative Zool-
ogy, Harvard University, kindly permitted access to
specimens of Turbinella pyrum under his care. The
photographs were prepared by H. Jade Kimbell.

LITERATURE CITED

Agrawala, Vasudeva S. 1965. Studies in Indian
Art. Vishwavidyalaya Prakashan, Varanasi, 1,
288 pp.

Banerjea, Jitendra Nath. 1941. The Development

of Hindu Iconography. Univ. of Calcutta Press,

Calcutta, 459 pp.
Bhattacharyya, B. 1958. Tlie Indian Buddhist

Iconography. K. L. Mukhopadhyay, Calcutta,

478 pp.
Edgerton, Franklin. 1964. (translator and inter-
preter). The Bhagavad Gita. Harper and Row,

New York, 202 pp.
Hornell, James. 1913. The chank bangle industry;

its antiquity and present condition. Mem.

Asiatic Soc. Bengal 3: 407-448.
Hornell, James. 1916. The Indian varieties and

races of the genus Turbinella. Mem. Indian Mus.

6: 109-122.
Hornell, James. 1951. Indian Mollusks. Bombay

Nat. Hist. Soc, Bombay, 96 pp.
Jackson, J. W. 1916. The Aztec moon-cult and its

relation to the chank-cult of India. Manchester

Memoirs 60 (5): 1-5.
Lamarck, J.-B. M. de. 1799. Prodrome d'une

nouvelle classification des coquilles. Mem. Soc.

d'Hist. Nat. de Paris,
Lightfoot, John. 1786. A catalogue of the Port-
land Museum. London, 194 pp.
Linnaeus, C. 1758. Systema Naturae. Tenth edi-
tion. Laurentii Salvii, Stockholm.
Munshi, K. M. 1963-1965. Krishnavatara. Bharatiya

Vidya, Bombay 2 and 3.
Roding, Peter F. 1798. Museum Boltenianum.

Hamburg, 199 pp.
Rubel, Mary. 1968. The Gods of Nepal. Bhimratna

Harsharatna, Kathmandu, 53 pp.
Sarma, D. S. 1948. The Tales and Teachings of

Hinduism. Hind Kitabs Ltd., Bombay, 180 pp.
Yokes, Emily. 1963. A possible Hindu influence at

Teotihuacan. Amer. Antiquity 29 (1): 94-95.
Yokes, Emily. 1964. The genus Turbinella (Mol-

lusca. Gastropoda) in tlie New Worid. Tulane

Studies in Geol. 2 (2): 39-68.
Walker, Benjamin. 1968. The Hindu Worid. George

Allen and Unwin Ltd., London 1, 609 pp.

THE NAUTILUS

January 29, 1974

Vol. 88(1)

SPECIES DIVERSITY OF TERRESTRIAL SNAILS
IN THE (;REAT smoky MOUNTAINS

Lowell L. Getz

Department of Zoology. University of Illinois
Urbana, Illinois 61801

ABSTRACT

A comparison was made of species diversity (Shannon index and number of
species) of larger terrestrial snails and gradients of moisture, temperature, and
diversity of dominant tree, shrub and herbaceous plants in the Great Smoky
Mountains. Estimates were also made of habitat breadth of the snails. There was a
positive correlation between snail diversity and the moisture regime and diversity of
dominant tree species. Tfiere was no correlation between snail diversity and
temperature, or shrub and herbaceous vegetation diversity. Comments arc also made
concerning the habitat breadths of the more common species.

INTRODUCTION

A series of terrestrial snail collections was made
as a special class project by the University of
Illinois Field Ecology Course to the Great Smoky
Mountains, Tennessee and North Carolina, 28-31
March, 1972, to compare species diversity in
various communities of the region with selected
environmental gradients. Although the data are not
extensive, they do show indications as to the
relationship between snail diversity and given
environmental factors. They are presented here
primarily to stimulate more intensive studies of
species diversity of snails in the various com-
munities within the Smoky Mountains.

AREA OF STUDY

Nine sites within eight of the community types
defined by Wliittaker (1956) were sampled. Except
where noted, special etTort was made to sample
within a representative site in each community
type. The following communities were sampled
(see Whittaker, 1956, for detailed descriptions of
the community types):

Red spruce-Mt. LeConte. on Bullhead Trail,
approximatel> 1,640 meters elevation.

Grass bald -The upper half of Andrew's Bald,
1,775 meters.

Beech gap-Approximately 1.5 km. north of
Indian Gap, 1,580 meters.

High hemlock-On the south side of U. S.
Route 411, at 1,200 meters. This site was typical

of Whittaker's eastern hemlock type at its upper
limits. Tlie tree canopy was composed almost
entirely of hemlock; shrub stratrum was a com-
plete cover of rhododendron. An herbaceous
stratum was essentially absent.

Low hemlock— Along the one-way road leading
from Cherokee Orchard to Gatlinburg, at approxi-
mately 745 meters. This site was characteristic of
Wliittaker's description of the eastern hemlock
type as it segregates from the Cove forest. The
tree stratum was composed primarily of hemlock,
but several deciduous species were also present.

Rtch pine-table mountain pine heath-Mt.
LeConte. along the Bullhead Trail at 1.100 meters.
The site had essentially an equal mixture of pitch
and table mountain pine. The rest of the vegeta-
tion corresponded to that as described by Wliit-
taker for the higher elevation pine heaths in the
Smoky Mountains.

Chestnut oak-chestnut-Mt. LeConte, a long
Bullhead Trail at 850 meters. Tlie site sampled
was in an area in which American chestnut
originally made up the major portion of the tree
canopy. The site is now occupied by a mixture of
young oak and other deciduous trees.

Virginia pine-Adjacent to the Cades Cove
Campgrounds, 550 meters.

Cove forest-Along the road in Greenbrier Cove,
2 km. beyond the turnoff to the Trillum Gap
Trail to Mt. LeConte. at 760 meters.

Vol. 88(1)

THE NAUTILUS

METHODS

A timed-interval search was used to sample all
communities. The twelve individuals involved in
the project each searched intensively for snails for
ten minutes at each site, resulting in a total of
two hours of searching. The search was conducted
so as to cover as much total area as possible. All
situations in which snails could be found were
searched; these included under the leaf litter,
under logs, fallen Umbs, and rocks, and in crevices
at the base of trees. All live snails and dead shells
were collected. The sampling of smaller species
was not complete, so only larger species were
included in the analyses; Retinella and other such
small snails were excluded.

Although there is bias in any collecting method,
the one used eliminated some obvious sources.
That the same twelve individuals sampled all nine
sites reduced bias from different collecting idio-
syncrasies; the same microhabitats received equal
coverage in each community. The inclusion of
dead snails in the analysis would tend to reduce
the bias resulting from suppression of snail activity
(and thus accessibility to collection) because of
lower temperatures in the early spring in those
communities at higher elevatons; there would be
more adequate representation . of the species
present in those communities.

Spot checks by the author of most of the same
community types on 12-13 April and 24-25 June,
1972 indicated the original data were representa-
tive of the abundance and diversity of species in
the various communities.

The species diversity of snails within each
community was measured by the Shannon index,
H' (Shannon and Weaver, 1963). The formula and
tables of Lloyd, et aL (1968) were used in the
calculations. Between-community species diversity
indices were also calculated. The former are used
to evaluate the influence of various environmental
factors on the species diversity of snails; the latter
are used to estimate relative habitat breadth of tlie
species.

RESULTS

Within-community species diversity-Table 1

summarizes the species diversity values witliin each
community and the correlation with the various
environmental gradients. The environmental gradi-
ents have been summarized from Wliittaker (1956,

1966). There was a positive correlation between
species diversity of snails and the moisture regime
in the nine communities (r^ = .87, P < .01;
Spearman Rank Correlation, Siegel, 1956). Like-
wise, there was a positive correlation between snail
diversity and the number of dominant tree species
present in each community (rg = .80, P =< .01).
There was no correlation between snail diversity
and temperature, shrub diversity, or herbaceous
vegetation diversity.

The major deviation from the correlation be-
tween the amount of moisture in the community
and snail diversity was in the Virginia pine
community. This community was judged to be the
third driest community studied, but ranked fourth
highest in snaU species diversity. The Virginia pine
community had one of the higher number of
dominant tree species (third highest) which may
be at least partly responsible for the greater snail
diversity.

The major deviation from the correlation be-
tween number of dominant tree species and
species diversity of snails is the high-elevation
hemlock. This community ranked third lowest in
the number of dominant tree species, but third
highest in snail diversity. The high-elevation hem-
lock, however, ranked as one of the more moist
communities studied (third highest) which may be
responsible for the greater snail diversity.

Habitat breadth-Between-community diversity
indices which have been used as an index of
habitat breadth are summarized in Table 2.

The immature Polygyridae had the widest range
of habitats. This would be expected since several
species were undoubtedly grouped into this cate-
gory; we, therefore, are not dealing with one
"habitat" but several and, thus, a wider apparent
habitat.

Pallifera sp. (probably only one species in-
volved) also had a wide habitat range, but the
numbers involved are rather low. The early
seasonal aspect undoubtedly biased the results
regarding this species. The observations made in
May and June of 1972 did indicate, however, that
the species was common in most of the habitats
studied.

Two or three species may have been involved in
the Stenotrema sp. category. Thus, the comments
concerning habitat breadth of the immature Poly-
gyrids also apply to this grouping.

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January 29, 1974

Vol. 88(1)

TABLE 1. Correlation of species diversity of terrestrial land snails and environmental gradients in the Great
Smoky Mountains National Park.

Community-

Number

H'^

Moisture^

Environmental Gradients

Type

Species'

Individuals

Temperature^

Vegetation Diversity^

Trees

Shrubs

Herbs

Spruce

2.9944

Cove Forest

2.9715

Hemlock (High)

2.8163

Virginia Pine

2.4806

Hemlock (Low)

1.9724

Oak-Chestnut

1.9039

Pitch-Table Mt.

Pine

1.5849

Beech Gap

0.3320

Grass Bald

' Includes two groupings (one genus and one family) considered as "species"

^To log base 2

^Ranked from low to liigh (1-9)

Of the more abundant species, Ventridens
elliotti, V. demissus, V. ligera, and Mesomphix
andrewsae obviously have relatively wide habitat
ranges while Vitrinizonites latissimus and Hap-
lotrema concavum have more narrow habitats. The
other species either had very low habitat breadths
or were collected in too few numbers (i.e.,
Mesodon christyi) to place much significance on
the relatively higli between-community diversity
indices.

Vitrinizonites latissimus was the most abundant
species and occurred in five communities. The
reason for the low H' appears to be related to its
association with graminoid vegetation. Observations
of the specific sites in wliich this species was
found indicated that it occurred primarily where
some type of grass or sedge was present. Gram-
inoid vegetation was most abundant in the grass
balds and the beech gap. V. latissimus is abundant
in these two communities; the species is much less
abundant and is spotty in its occurrence in the
other communities studied.

DISCUSSIONS AND CONCLUSIONS

Tlie data obtained in this study indicate
moisture and/or number of dominant species of

trees are primary factors influencing species diver-
sity of terrestrial snails within communities in the
Smoky Mountains. Tliis differs somewhat from the
trends in species diversity of insects in the Smoky
Mountains observed by Wliittaker (1952). He
found insect diversity to be greatest in the
intermediate moisture conditions, with lesser diver-
sity at both moist and dry extremes.

Terrestrial snails (especially the families col-
lected in this study) are relatively susceptible to
desiccation. Tliose species with less tolerance to
desiccation would tend to be restricted to the
more moist communities. There would, therefore,
be a gradual "filtering" process with the less
tolerant species dropping out, as one progresses
toward the drier communities. Tlie density of
snails may not show such a relationsliip, however,
since those species adapted to dry conditions
could develop higli population densities in such
sites. Except for the Virginia pine community
these relationships are borne out by the data
(Table 1).

The beech gap community is of special interest
in that more individuals were collected here than
in any other community, but the diversity index
was next to the lowest of the nine communities.

Vol. 88(1)

THE NAUTILUS

TABLE 2. Habitat breadth of terrestrial snails in
the Great Smoky Mountains National Park.

Species

Total Total

Individuals Communities

Polygyridae (immature)

2.2109

Pal'lifera

1.9182

Mesomphix andrewsae

1.7712

Stenolrcina sp.

1.7575

Ventridens ligera

1.6164

V. elliotti

1.5040

V. demisstis

1.4198

Mesodon christyi

1.3710

M. perigraptus

1.0000

Vitrinizonites latissimus

0.9256

Haplolrema concanim

0.7733

Mesodon downieanus

0.7219

Mesomphix subplanus

Triodopsis trideiUata

Mesodon andrewsae

Ventridens sp. (immature)

Mesodon ferrissi

M. clauses

Mesomphix sp. (immature)

Mesodon rugeli

Mesomphix sp. (adult)

M. vulgatus

Ventridens intertextus

To log base 2.

Almost all the specimens from this community (77
of the 81 collected) were Vitrinizonites latissimus.
The beech gap has trees and a relatively deep leaf
litter which moderate the physical environment
(especially the surface soil moisture) in addition to
the presence of a dense stand of grass. The only
other community with significant grass is the grass
bald. Trees and shrubs are very sparse in this site,
however, so that there is not a cover of leaf litter
to modify the surface soil moisture regime. A very
low moisture availability in the grass bald may be
responsible for the low populaton density of V.
latissimus in this site.

Since trees furnish most of the organic matter
to forest soils (Lutz and Chandler, 1946), there
would be a positive correlation between tree
species diversity and diversity of nutritional and
physical properties of the soU. This microhabitat
diversity in turn would have a direct influence on
the diversity of terrestrial snails (Burch, 1956) and
may partially account for the correlation between
tree diversity and snail diversity in the commu-
nities studied.

Much more data would be necessary to evaluate
the habitat breadth of all the species of the
region. The results of the present study do-

indicate, however, that Mesophix andrewsae has
broader habitat tolerances than most of the other
species. Vitrinizonites latissimus displays more
narrow habitat requirements. Tliis apparently re-
sults from an association with graminoid vegeta-
tion. Such vegetation occurs in abundance only in
a few habitats. That these sites are also relatively
xeric indicates that the primary factor influencing
the distribution of this species is not moisture.

Owing to the rather small amount of total
collecting effort involved in the current study,
more extensive analyses and extrapolations do not
appear warranted. I think this preliminary study
does indicate, however, the utility of making a
more intensive study of this type. With compre-
hensive sampling of these and other community
types in the region, one should be able to arrive
at more definitive conclusions regarding the factors
influencing the diversity and habitat breadth of
terrestrial snails.

ACKNOWLEDGMENTS

I wish to tliank the members of the Spring
1972 Field Ecology Course from the University of
Illinois for cooperating with the field collections
from which the diversity indices were calculated.

LITERATURE CITED

Burch, J. B. 1956. Distribution of land snails in

plant associations in eastern Virginia. Nautilus

70: 60-64; 102-105.
Lloyd, M., J. H. Zar, and J. R. Karr. 1968. On

the calculation of information ~ Theoretical

measures of diversity. Amer. Midi. Nat. 79:

257-272.
Lutz, H. J. and R. F. Chandler. 1946. Forest

Soils. John Wiley and Sons, New York.
Shannon, C. E. and W. Weaver. 1963. The

Mathematical Theory of Communication. Univ.

Illinois Press, Urbana.
Siegel, S. 1956. Nonparametric statistics for the

behavioral sciences. McGraw-Hill, New York.
Whittaker, R. H. 1952. A study of summer foliage

insect communities in the Great Smoky Moun-
tains. Ecol. Monogr. 22: 1-44.
Whittaker, R. H. 1956. Vegetation of the Great

Smoky Mountains. Ecol. Monogr. 26: 1-80.
Whittaker, R. H. 1966. Forest dimensions and

production in the Great Smoky Mountains.

Ecol. 47: 103-121.

10 THE NAUTILUS January 29, 1974 Vol. 88(1)

A NEW SPECIES OF HAWAIIAN GYRINEUM (CYMATIIDAE)

Hal Lewis

Research Associate, Department of Malacology

Academy of Natural Sciences of Philadelphia

Pliiladelphia, Pa. 19103

ABSTRACT

Gyrineum louisae is described as a new species from Hawaii The unusual sculp-
ture of the protoconch is described and figured Tlie protoconchs of Gyrineum
gyrinum (Linnej, Gyrineum nulator (RodingJ, Gyrineum bituberculare (Lamarck),
and Gyrineum concinnum (Dunker) are figured for comparison. Various taxonomic
characters of the genus are discussed.

INTRODUCTION

In the June 1963 issue of the Hawaiian Shell
News, Dr. C. M. Burgess illustrated a species ta-
ken during the Pele expedition and suggested
that it was "similar to a Bursa. " The figured
specimen is actually a new species of Gyrineum,
Since that time no other specimens have been
reported. Recently the figured specimen was
brought to me for examination by Dr. Alison
Kay of the University of Hawaii during her visit
to the Academy of Natural Sciences of Philadel-
phia. The morphology of tlie shell and the shape
and proportion of the protoconch are typical of
the genus (figs. 1-3 and 6). Microscopic examina-
tion of the protoconch reveals a remarkable can-
cellate sculpture wliich is unique to Gyrineum
louisae. The regular, fine sculpture on the whorls
of Gyrineum louisae are clearly distinct from any
other species in the genus.

HISTORICAL DISCUSSION OF
THE GENUS GYRINEUM

A great deal of confusion has existed con-
cerning the proper use of Gyrineum Link, 1807.
Many authors, including Wenz (1961, p. 1073),
have considered this to be a name properly ap-
plied to a bursid genus. This misuse still persists
in recent Uterature, as well as in the systematic
arrangement of various museum collections.

Dall (1904, p. 115) discussed Link's genus and
pointed out that there is a mixture of species
included in the original description which "seems
to have been based wholly on the presence of
symmetrical lateral varices, and included species

Uke M. gyrinus Linne, which have no posterior
canal." He also stated that "Montfort 1810, saw
more clearly and put the ranelliform tritons by
themselves under the name of Apollon . . . with
Murex gyrinus (Linne) Gmelin as type." Dall
confirmed the validity of Gyrineum as a cymatiid
genus, designating Murex gyrinus Linne, 1758, as
the type, and listing Apollon as a synonym of
Gyrineum. In spite of the wide-spread circulation
of Dall's paper, many authors mistakenly contin-
ued to use the name Gyrineum for a bursid
genus and the name Apollon for the cymatiid
genus which should properly be called Gyrineum,

Cernohorsky (1967, p. 322) agreed with Dall
and pointed out that the type for Apollon
Montfort, 1810, is A. gyrinus (=Murex gyrinus
Linne). Therefore Apollon is synonymous with
Gyrineum Link, 1807. He also stated that
Rovereto's designation (1899, p. 106) of
Gyrineum spinosum (Dillwyn, 1817) as the type
species for Gyrineum is invalid because spinosum
was not originally included in Link's genus.
Gyrineum spinosum { = G. echinatum Link,
1807) belongs to the bursid genus Bufonaria
Schumacher, 1817. Link's list included G.
echinatum Link, G. rana (Linne) Link, G.
bufonium, G. natator, M. gyrinus and G.
verrucosum, a mixture of Bursa and Gyrineum,

It does seem unfortunate that the rules of tax-
onomy cause us to recognize Gyrineum and to
synonymize Apollon simply because Link in-
cluded a species which, in fact, is not typical of
the genus he described. This is especially true
when we realize the consequential confusion
which has existed for almost 167 years concern-

Vol. 88(1)

THE NAUTILUS

ing the misuse of Gyrineum as a bursid genus.
As recently as August 1973, Kilias (p. 13) per-
sists in the use of Apollon for Gyrineum It is
also unfortunate when we realize how much
more clearly Montfort understood the relationsliip
of the species he included in Apollon.

Species of Bursa and Gyrineum are easy to
confuse because of the similarity of shell mor-
phology, especially since botli have more or less
laterally aligned varices. However the presence of
the open posterior anal canal in the Bursidae and
the absence of it in the Cymatiidae as a distin-
guishing characteristic is widely accepted and
apphes very well in this instance.

Genus Gyrineum Link, 1807

Gyrineum Link, 1 807, Beschreibung der Naturalien
Sammlung der Universitat zu Rostock, p. 123. Type
species, Murex gyrinus Linne, 1758, subsequent
designation W. H. Dall, 1904.

Apollon Montfort, 1810, Conchyliologie
Systematique, et Classification Methodique des
Coquilles: p. 570-571.

Description — Shells range in length from 20
to 45 mm. The genus is typified by laterally
aligned varices which on some species actually
connect to form a smgle continuous varix on
each side. This gives the whorls a distinct bilater-
ally compressed appearance. Tliey are sculptured
by spiral cords and axial ribs which form fine to
coarse beads or nodules where they cross. The
aperture is oval to round with dentition usually
present on the inner edge of the outer lip. The
anterior siphonal canal is short. The radula is ta-
enioglossate and is differentiated from other
Cymatiidae by the flat character of the base of
the rachidian which contrasts with the arched
base typical of the rachidian of most Cymatiidae.
The opercula of all species examined are terminal
in pattern, with the exception of occasional dam-
aged specimens which have regenerated with a
nucleus. This condition has been observed in
other genera of the Cymatiidae. The protoconchs
of the various species are very similar (figs. 6-10)
with the exception of G. louisae which has a
fine regular canceUate sculpture. Jaws were pre-
sent in all species examined.

Gyrineum louisae
new species, Lewis

Figs. 1-3

Description - SheU white, 19 mm. in lengtli
and 12 mm. in width at the periphery. There
are 6 whoris producing a spire of 57 . The outer
lip is thickened at the final varix. The 9 varices
do not align but are slightly offset (fig. 3).
There are 13 spiral cords crossed by 16 axial
ribs between the varices which form a very fine
beaded pattern. The axial ribs do not extend to
the varices but the spiral cords cross the varices
forming 13 distinct fine ridges on tire varix at
the outer lip. Tlie siphonal canal is very short,
measuring only \^A mm. from the base of the
outer lip to the tip of the canal. There is a
glossy raised peristome on the inner edge of the
outer hp which continues to the upper edge of
the glazed parietal waU. The protoconch is cover-
ed by a fme network of axial ribs and spiral
cords (fig. 6) but is similar in shape to other
species in the genus (figs. 7-10). The operculum
and animal are unknown.

The distribution is unknown except for the
type locahty where the holotype was taken on
the Pele expedition at 180 fathoms, off Pokai
Bay, Oahu, Hawaii. The holotype is deposited in
the B. P. Bishop Museum, Honolulu.

1 take great pleasure in naming this species
after my wife Louise in small repayment for her
continued patience during my work with the
Cymatiidae. It is hoped that there will be no
confusion with the little used name Bursa louisa
M. Smith, 1948, wliich is a synonym for Bursa
caelata (Broderip 1833) from the Panamic region.

Differentiating features - Gyrineum louisae is
most similar to Gyrineum natator but differs by
being smaller, lacking pigmentafion by having 13
spiral cords instead of 8. The protoconch of na-
tator is smooth.

Gyrineum louisae differs from Gyrineum
gyrinum, the type of the genus, by being small-
er, lacking pigmentation and the color bands of
gyrinum, having finer sculpture with 13 spiral
cords instead of 8. Tlie protoconch of gyrinum
lacks the sculpture of louisae.

Although most species of Gyrineum are pig-
mented, Gyrineum pusillum (Broderip, 1832) is
also white, and species such as hirasei Kuroda

12 THE NAUTILUS

January 29, 1974

Vol. 88(1)

FIGS. 1-1 l,t'xplanatioii on opposite page.

Vol. 88(1)

THE NAUTILUS

and Habe, 1964 and bituberculare Lamarck, 1816
can be very pale.

FOSSIL LITERATURE

An investigation was made in order to deter-
mine whether or not this species had been
named in the fossil Uterature. Special attention
was given to the various species from Java and
Timor described and discussed by K. Martin. A
partial list of tliese papers is included in the
cited Uterature. No fossil species was discovered
wliich can be considered to be this species.

ACKNOWLEDGEMENTS

I wish to thank Dr. AUson Kay, University of
Hawaii, for bringing the specimen to Philadelplria
so that I could examine and describe it; the Bish-
op Museum of Hawaii for the loan of tlie spec-
imen and Dr. R. T. Abbott, du Pont Chair of
Malacology, Delaware Museum of Natural History
for reviewing tliis manuscript.

LITERATURE CITED

Cernohorsky, Walter O. 1967. The Bursidae, Cyma-
tiidae and Colubrariidae of Fiji. The VeUger 9 (3):
310-329, pis. 42-46, 14 text figs.

Dall, WiUiam H. 1904. An Historical and Systematic
Review of tl;e Frog-Shells and Tritons, Smith-
sonian Miscellaneous Collecrions 47 (1475)
(Quarterly Issue) 1 14-144.

Kilias, Rudolf Dr. 1973. Famiha Cymatiidae. Das
Tierreich 92 (I-VIII) 1-235, 149 text figures.

Link, H. F. 1807. Beschreibung der Naturalien-
Sammlung der Universit'at zu Rostock.

Martin, K. 1879. Die TertiarscWchten auf Java. pp.
53-55, pi. 10.

Martin, K. 1884. Beitrage zur Geologie Ost-Asiens
und Australiens 3 Palaeontologjsche Ergebnisse von
Tiefbohrungen auf Java, Nebst Allgemeineren
Studien Ueber Das Tertiaer von Java, Timor and
Einiger Anderer Inseln, pp. 129-139, pi. 7.

Martin, K. 1916. Sammlung des Geologjschen
Reichs-Museums in Leiden, (2): 242-243, pi. 3.

Montfort, Denys De 1810. Conchyliologie System-
atique, et Classification Methodique des Con-
quiUes: 2: 570-571.

Rovereto, Gaetano 1899. Prime Ricerche Sinoni-
miche sui generi dei gasteropodi. Atti della Societa
Ligustica di Scienze Naturali e Geografiche, 10:
101-110.

Smith, Maxwell 1948. Triton, Helmet and Harp
SheUs, Winter Park, Florida, pp., V+57, 16 pis.

Wenz, Wilhelm 1961. Handbuch der Palaozoologie 6
(1) Gastropoda 1056-1076.

FIG. 1-3. Gyrineum louisae new species. Lewis,
Holor\'pe, 180 fathoms off Pokai Bay, Oahu, Hawaii
19mni X 12 mm

FIG. 4, Gyrineum gyrinum (Linne), North side of
Kyangel Isl. Palau district. West Carolines 30 mm x
20 mm

FIG. 5, Gyrineum natator (Rbding), India 38.5 mm
X 24 mm.

FIG. 6, Protoconch of Gyrineum louisae Lewis,
Holotype. 180 fathoms off Pokai Bay, Oahu, Hawaii
X 17.

FIG. 7, Protoconch of Gyrineum bituberculare
(Lamarck), Tayabas Bay, Philippines, x 17.

FIG. 8, Protoconch of Gyrineum natator (Rbding),
Bay of Bengal, India, x 17.

FIG. 9, Protoconch of Gyrineum gyrinum (Liim8),
West Carolines, x 17.

FIG. 10, Protoconch of Gyrineum concinnum
(Dunker-, Obhur, Saudi Arabia, x 17.

FIG. 1 1 , Larval shell of Gyrineum natator (Roding),
Bay of Bengal, India, with periostracal formation
showing spiral ridges somewhat similar to the spiral
cords formed on the protoconch o/ Gyrineum louisae
Lewis. (In the Cymatiidae, the shell sculpture of
cords and ribs usually corresponds to periostracal
formation.)

THE NAUTILUS

January 29, 1974

Vol. 88(1)

GROWTH STUDIES ON THE GENUS C£"/?/r///fW (GASTROPODA: PROSOBRANCHIA)
WITH NOTES ON ECOLOGY AND MICROHABITATS

Richard (Joseph R.) Houbrick '

Department of Biology

University of South Florida

Tampa, Florida 33620

ABSTRACT

The growth rates and general ecology of four species o/ Cerithium were studied in
Florida. Comparative ecological observations on worldwide species of the genus are made.
All Cerithium species are shallow water subtidal or intertidal dwellers and most are
associated with marine grasses and algae. Some species occur in large populations. They
appear to be selective algal-detritus feeders and have style-bearingstomachs with complex
ciliary sorting mechanisms.

Species in Florida spawn from winter through spring, grow from juveniles to adult
stages in a few months, and have life spans of about one year. Predation on Cerithium
species occurs by carnivorous mollusks, crabs, starfish and bony fish. Smaller Cerithium
species tend to be intertidal

INTRODUCTION

The genus Cerithium is common in a variety of
shallow-water, tropical and subtropical habitats.
There are few accounts of the ecology of this genus
beyond some scattered remarks in various papers
dealing with anatomy and systematics. Few studies
have been made on the ecology of littoral gastropods
in the tropics. The growfth rates of marine tropical
and subtropical benthic mollusks are little known
(Lewis et al, 1969) while those living in temperate
and cold climates have been more thoroughly
investigated. Literature concerning growth in inter-
tidal marine organisms has been reviewed by Moore
(1958), NeweU (1965, 1970), and WUbur and Owen
(1964). Lewis et al. (1969) have surveyed the
literature concerning the factors which are known to
influence growth rates (gonadal maturation, age,
temperature, food supply, and environmental fac-
tors). The environmental factors have also been
discussed by Vohra (1970). Houbrick (1970; 1974, in
press) recently defined the mode of reproduction in
Cerithium species from the Western Atlantic.

The account which follows is primarily concerned
with four species of Cerithium common in Florida, C
muscarum Say, 1832 (Fig. 4, D), C lutosum Menke
1828 (formerly C. variabile^ ) (Fig. 4, B) C. ebumeun.

Present Address: Supervisoi for Invertebrates, Smithsonian
Oceanographic Sorting Center, Smithsonian Institution,
Washington, D.C. 20560.

Bruguiere 1792 (Fig. 4, C) and C atratum (Bom,
1778) {=€. floridanum Morch^]. A hterature survey
and observations on other worldwide species of
Cerithium and Rliinoclavis are also included.

MATERIALS AND METHODS

This study is based mainly upon material collected
in Florida. Observations were made in the field and
laboratory from September 1968, through May 1971.
Supplementary field work was done at the Eniwetok
Marine Biological Laboratory, Marshall Islands, in
August 1970, and at Carrie Bow Cay, British
Honduras, in May 1972. In Florida, monthly samples
and observations, when possible, were made from a
total of four field stations, while other areas in the
state were visited less regulady. The sites selected for
ecological and growth studies in Florida represent
several environmentally different habitats and are
located in different marine zoogeographical pro-
vinces. The data collected on the populations of
species studied at these sites does not necessarily
apply to other populations of the same species in
other parts of their ranges.

The four main stations in Florida were located at
Port Everglades (lat. 26°6'N, long. 80°4'W), Bear Cut
(lat. 25°44'N, long. 80°8'W), Dunedin (lat. 28°2'N,

C. varwbile C. B. Adams 1845 is a synonym of C. lutosum.
This will be documented in a later paper.

C. floridanum Mbrch, 1876 is a synonym of C. atratum.

Vol. 88(1)

THE NAUTILUS

long, 82°45' W), and Mullet Key (lat. 27°35'N, long.
82°44'W). The first two stations are located on the
lower east coast of Florida where the environment
and fauna are largely tropical and Caribbean in
nature, while tiie latter two are located along the
central Gulf coast of the state, where the marine
fauna and environment are subtropical and largely
Carolinian in composition. More detailed descriptions
of the four stations may be found in the body of this
paper.

Quantitative monthly data on temperature, sa-
hnity, and tides were taken. Monthly measurements
of the growth of populations of C. muscarum, C.
lutosum, C. atratum, and C. ebumeum were made.

For growth studies, samples from the four field
stations were collected with a mesh push-net in grass
beds, sand, and mud habitats. Material was passed
through a screen of 0.25-cm mesh and the samples
removed. Algae and marine grasses were washed in
fresh water to collect any young snails in the
populations. Collecting was limited to about one hour
at each station. Measurements of the monthly
samples were made in the laboratory. The length of
the sheUs was determined to the nearest 0. 1 mm with
vernier calipers. In most cases, 50 or more were
measured. Snails with badly eroded apexes were not
measured. Length was determined as tlie distance
from the apex of the shell to the base of the aperture,
and width by measuring the thickness of the last
whori. Difficulty was encountered in width mea-
surements because of the random presence or absence
of varices on the body whorl. For this reason, length
measurements were relied on in making size
frequency plots. Size-frequency analysis was made on
monthly measurements and the mean, mode, standard
deviation, and range were computed. The addition of
new whorls and increases in shell length were taken as
indications of new growth. To determine population
densities of species with obvious high densities,
random samples were taken by dropping a lOcm
square metal frame over the area to be sampled. All
animals appearing within the frame were counted and
Stein's two-stage samphng technique (Steel and
Torrie, 1960) was used to compute average densities.
Living animals were maintained at a temperature of
25 C in aquaria of seawater with a salinity of 34°/oo.
The snails were fed on local algae, marine grasses, and
detritus from Tampa Bay. Observations and dis-
sections of living animals were conducted to
determine food preferences and stomach contents.

Associations, kinds of predators, and behavior were
also noted and are herein recorded. However, these
observations were not of a quantitative nature and
may not be significant.

Various sites in Florida, the Caribbean and the
Pacific, were also studied to collect comparative data
on other species oi Cerithium.

ECOLOGY OF CERITHIUM MUSCARUM

Habitat

Cerithium muscarum, throughout its range, is
found associated with marine grasses such as Thalassia
testudinum, Ruppia maritima, Halodule wrightii and
Syringodium sp.

Cerithium muscarum is a common inhabitant of
bays and other estuarine areas, but is also found in
the open sea in areas shallow enough to support
extensive beds of grass such as occur on the Gulf
coast of Florida.

A population of C. muscarum was studied

AMJ JA SONDJ FMAIMJ J ASONDJ
MONTHS OF YEAR

Fig. 1. Cerithium muscarum. Growth of population
expressed as a measure of shell length. Vertical lines
represent range, horizontal lines the mean, and bars,
the standard deviation. Solid bars represent months
of oviposition.

intensively at the north end of Mullet Key in the
entrance of Tampa Bay, Florida. This is a shallow
estuarine habit with mangroves constituting the
predominant shore line vegetation. The general
ecology of Tampa Bay has been treated by Dragovich
and Kelly (1964). There is httle wave action at Mullet
Key and the mean fidal range is about 60 cm. Average
water temperature at this station was 25.3 C, ranging
from extremes of 14°C in January 1970, to 33°Cin

THE NAUTILUS

January 29, 1974

Vol. 88(1)

June 1969. Mean salinity was 34.6°/oo with a range
from 31°/oo in February 1969, to a high reading of
37°/oo in August 1970. Salinity levels appear to be
relatively stable, although heavy rains may lower
them appreciable for short periods. Some wave action
occurs when winds are strong causing considerable
amounts of debris and detritus to be deposited in the
intertidal zone and on the beaches. The water is
generally clear during the winter and spring, but is
turbid in summer and fall.

Ccrithium muscanim is found living in the beds
of Thalassia and Ruppia about 16m offshore, just at
and below the low tide mark. Occasional minus tides
expose the whole area. The substratum is sand but
quantities of detritus and debris collect about the
roots and in between the blades of the Thalassia and
Ruppia. Cerithium muscarum is found browsing upon
the epiphytic algae on Thalassia leaves and also
partially burrowing in or crawUng on the detritus and
sand. Its distribution is limited to the TJialassia and
associated detritus.

This species is also common in HiUsborougli Bay,
Florida, a more brackish environment, where it is
found in beds oi Ruppia near submerged oyster bars.
I also observed it in beds of Thalassia in Biscayne
Bay, Florida, and the Florida Keys. Tabb, Dubrow
and Manning (1962) found it in the shallow brackish
waters of Florida Bay.

Behavior

Cerithium muscanim is a continual browser with a
monotaxic type of locomotion. Captive specimens
exhibit shadow responses by quick withdrawal into
their shells. When the water is stirred by wave action,
C. muscanim buries itself in the sand at the bases of
the Thalassia plants. During low tides, sliglit
clustering of individuals occurs.

Food and Feeding

Cerithium muscarum feeds and deposits fecal
pellets intermittently. In the aquarium it eats the
sand and surface deposits on the bottom as well as
epiphytic algae on Thalassia blades. Decaying
Thalassia leaves are also consumed. Stomach contents
consist of sand grains, detritus, and green algae such
as Cladophora and ChaelDmorpha. Fecal pellets
contain the same type of material as is found in the
stomach, only many of the algal cells are evacuolated.

Associations and Predators

In some habitats, the potamidid snail, Batillaria

minima, is associated with C muscanim but it
occupies a higher tidal zone. No mi.ving between the
two species occurs. Frequently, young Crepidula
fornicata are found on the siphonal canal of the shell
of C. muscarum Seventy-two per cent of the Mullet
Key population harbor Crepidula fornicata on their
shells. The digenetic trematode, Mesostephanus
appendiculatoides, found in birds, uses C muscanim
as its first intermediate host (Hutton and Sogandares-
Bernal , 1960). In Tlialassia communities of the
Florida Keys and Biscayne Bay, C muscarum is
occasionally found with C ebumeum.

Cerithium muscanim is attacked and eaten by
crabs of the genera Callinectes, Menippe, and Libinia.
Numbers of shells with broken aperatures indicate
tliat predation by crabs is common. 1 also observed
the carnivorous snails, Melungena corona, Busycon
contrarium, Fasiolaria tulipa, and Pleuroploca gigan-
tea preying upon C muscarum Shells with drilled
holes indicate that naticid snails (Polinices, Natica,
Sinumj as well as muricid snails (Murex, Eupleiira)
may also be predators. Stingrays and horseshoe crab,
Limulus, are abundant in the study area and are also
suspected predators.

Growth

Size frequency analysis (Table 1 ) indicates that the
monthly mean shell length of tiie Mullet Key
population of C muscarum fluctuated between 23-16
mm (Fig. 1). Oviposition takes place from January
through July and development is direct with no
pelagic stages (Houbrick, 1970). Althougli a few
young snails were found in die population during the
spring, young snails (5- 10mm) were most common in
August and September. Growth rates were rapid. The
mean shell length of the population, 16 mm in
August, had reached 21 mm by Octt)ber. Thus, the
new generation took only three montlis to reach an
adult size. The largest individuals taken were 26 mm
in length and were found in eariy spring.

In addition to increase in shell length, another
indication of growth is a thin-lipped shell aperture,
formed during the addition of new whorls. Tliis was
most evident during tlie fall and eariy winter
(September-December). Monthly statistics on this
population were maintained, and a summary is given
in figure 1 .

C. muscarum was most abundant during the winter
when the density of the population averaged 25
snails/m^. By late spring, the population size began to

Vol. 88(1)

THE NAUTILUS

decrease and during the summer was the lowest prior
to the hatching of new snails. The new generation
appeared in late August. In the fall, new adult
individuals were easily differentiated from the
previous generation on the basis of their shells, which
were erosion-free, more colorful, and free of marine
foulers. Snails over a year old had eroded shells,
covered with oysters, barnacles, brozoans, etc. On the
basis of the number of new individuals present in the
population by November, and the lack of older snails,
C. muscarum probably has a life span of about one
year.

ECOLOGY OF CERITHIUM LUTOSUM

Habitat

Cerithium lutusum exliibits great ecological diver-
sity in terms of substratum preference. I collected it
on substrata ranging from fine, muddy sand to
limestone slabs and beachrock. Occasionally, it occurs
in beds of Thalassia, but it is almost always associated
with some type of algae. Cerithium hitosum
(occurring in both estuarine and high-salinity
environments) is euryhaline by comparison with most
other species of Cerithium

Detailed studies on this species were carried out at
Port Everglades, Florida. This station is located in
soutlieastern Florida between Ft. Lauderdale and
Hollywood. It is a deep-water port on the Intracoastal
Waterway, which opens to the ocean by a narrow
inlet. In the vicinity of the port, tlie Intracoastal
Waterway branches into several smaller canals, one of
which is known locally as "Whiskey Creek". This was
the site of the study and is a shallow, brackish tidal
canal about 1 1 m wide extending for a length of
about 2 mi. At its center it is about 2 m deep at high
tide and slopes gradually upwards to the banks. Tidal
fluctuations are about 1 m and generate a current
between tides. The average bottom water tempera-
ture, recorded monthly, throughout this study was
28.4 C, ranging from 20°C in February 1969, to
35 C in September 1969. Mean salinity was 27.5°/° o
ranging from a low of 13°/oo in October 1969, to a
high reading of 35°/°° in December 1969. Salinity is
variable and may drop rapidly after periods of
heavy raintali. Because there is no wave action, the
bottom and intertidal zone are stable, but detritus is
distributed and redeposited by tidal action. The canal
bottom is sandy with occasional areas of muddy
sediment. The sand is composed of broken shell and

is coarse. The water, although darkly stained by
tannic acid from the mangroves, is seldom turbid or
muddy. The canal is bordered on one side with
Rhizophora mangle, the red mangrove, and with open
beach sand on the other side. Portions of the bottom
are covered with algae, primarily Gracilaria folifera,
Hypnea musciformis and Chaetomorpha gracilis. A
vascular plant, Halophila balionis, is also present as
well as Halodule wrightii.

Cerithium lutosum occurs in great numbers
(average density of 3,400/m^ ), occupying a zone 2 m
wide along the shallow banks of the canal from the
high-tide mark to just below the low-tide level. The
highest concentration of snails (15,000/m^) is just
above the low-water mark to inid-tide level. Much
detritus is deposited in this area during tidal changes.
Cerithium lutosum is closely associated with the
green alga, Chaetomorpha gracilis. This alga covers
the substratum and the shells of the snails. 1 also

I rt

I 15
O

-l_l_

I I ■ ■ '

-L.

MJ J ASONDJ FMAMJ J AS OND
MONTHS OF YEAR

Fig. 2. Cerithium lutosum. Growth of population
expressed as a measure of shell length. Vertical lines
represent range, horizontal lines the mean, and bars,
the standard deviation. Solid bars represent months
of oviposition. Asterisks represent months of
oviposition when other measurements were not made.

observed Cerithium lutosum on intertidal beach rock
along Bear Cut, Key Biscayne, Florida, where it is
likewise abundant (average density of 1,700/m^),
clinging to the rocks or partially buried in mats of the
filamentous green alga, Enteromorpha. The highest
concentrations at Bear Cut were just above the
low-tide mark (6,500/m^). This species was also
abundant on intertidal coral rock at Pigeon Key,
Florida. In the Laguna de Terminos, Campeche,

THE NAUTILUS

January 29, 1974

Vol. 88(1)

Mexico 1 found it in the brackish lagoon, intertidally,
on most algal-covered rocks. At Portcte, Costa Rica,
and on Carrie Bow Cay, British Honduras, I observed
it in shallow water Thalassia communities. Jackson
(1972) found large populations of C variabile (now
C. lutusum) in Thalassia in Jamaica.

Behavior

Cerithium lutosum moves frequently with tidal
changes. It was found crawling on the substratum and
also partially burrowing in the sand. Wlien tidal
currents are strong the population orients itself with
tlie anteriors of the shells facing the current and then
buries itself almost completely. The snails emerge
when conditions are more stable. Their mode of
locomotion is monotaxic, direct. Cerithium lutosum
is frequently exposed to the sun at low tide and is
able to tolerate desiccation for this period. It is
capable of surviving water temperatures in excess of
41°C (Jackson, 1972). Light clustering of individuals
occur during low tide, but not to the extent observed
by Moulton (1962) in some Australian species. In the
laboratory, the snails appear to be photopositive but
are repelled by strong light and will also quickly
withdraw into their shells in response to a shadow.

Food and Feeding

Observations in the laboratory indicate that C.
lutosum is a relatively continuous feeder. It
constantly rasps the substratum, engulfing algae and
detritus, pausing occasionally, and intermittently
deposits strings of fecal pellets. Stomach contents
revealed a variety of material such as diatoms,
Foraminifera, sand grains, blue-green and green algae,
especially Euteromorpha and Chaetomorpha, and
much detritus. It is difficult to determine what is
selectively digested in the complex sorting system of
the stomach. The above-mentioned stomach contents
are also found in the fecal pellets.

Associations and Predators

In all habitats and locations studied, the potamidid
snail, Batillaria minima, which closely resembles C
lutosum, is found just above the tidal zone level
occupied by C lutosum and upwards to the high tide
mark. At the Port Everglades site there is a zone of
mixing between the two species about 10 cm wide,
but they generally tend to remain separate. They
both feed on algae and detritus.

Predators that eat C lutosum are the blue crab,
Callinectes sapidus, hermit crabs of the genus
Pagurus. and the snail Melongena corona. Raeihle
(1968) observed the snail, Mitra floridana eating the
young of C. lutosum. Jackson (1972) recorded
predation of C. lutosum in Jamaica by the naticid
snails Polinices and Natica. Predation by rays is
suspected because they have been noticed frequently
in the study areas. Other suspected predators are the
horseshoe crab, Limulus, the spider crab, Libinia,
bony fishes and wading birds.

Growth

C. lutosum has direct development (Houbrick,
1970; 1973, in press), and size-frequency data (Fig.
2) indicate tliat adult size is reached in about one
year. Size-frequency analysis of the Port Everglades
population shows that the monthly mean shell length
varies between 7-11 mm througliout the year. The
largest snails were 16 mm in length and were found in
March. Frequent oviposition occurred from fall
through early spring, with minor egg-laying, activity
seen at other times of the year (Fig. 2). Most of the
young snails were found from April tlirough
September, indicating that development and growth
of the new generation occurs during the summer
months. The mean length of the snails during this
period was 8 mm Average growth in length was most
rapid in the fall (October-November). Size-frequency
data indicate that young snails reach adult size in a
few months. It was not possible to determine tlie life
span of C. lutosum with accuracy because attempts to
raise newly-hatched snails to adulthood were
unsuccessful. However, it appears that snails in the
Port Everglades population live about one year.
Fluctuations in die size of the population (in
numbers of individuals) occur during late summer and
early fall when both generations are found together.

ECOLOGY OF CERITHIUM EBURNEUM
Habitat

Cerithium ebumeum occurs in the shallow sandy
areas associated with Thalassia. This species was
studied at Bear Cut, Key Biscayne, Florida. Bear Cut
is an inlet at the north shore of Key Biscayne leading
into Biscayne Bay. Tlie general ecology of this region
has been treated in detail by McNuity (1^62) and an
ecological bibliography of the area has been compiled
by Morrill and Olson (1955). In the shallow water

Vol. 88(1)

THE NAUTILUS

along the north shore of Key Biscayne, the plants
Thalassia, Valonia and Padina are common. These
shallow areas and their associated biota extend up to
the sublittoral zone. Tidal fluctuations are about 1 m
and flushing currents of considerable strength may be
generated by changing tides. During the sampling
periods the average bottom water temperature was
26.7°C, ranging from 22°C in December 1970, to
33 °C in August 1969. The average salinity was
37°/ oo with a low of 34°/ oo in August 1970, and a
high of 40°/ oo in December 1969. The water is
usually clear, but can become turbid due to strong
winds and rough seas.

The population of C. ebumeum occurred sub-
tidally, just beyond the low tide mark (MLT), but
was never observed completely exposed. The snails
were dispersed on a sandy substratum near beds of
Thalassia at a density of about 4/m^. Populations
observed in tlie Florida Keys and British Honduras
occupy the same kind of habitat.

Behavior

Cerithium ebumeum is an active snail and crawls
on the surface of algal-covered stones and shells
between the grass beds as well as on the blades of
Thalassia. The snails were normally on the surface of
the substratum but some burrowing was occasionally
observed. This snail Uved well in captivity. Its mode
of locomotion is monotaxic, direct.

Food and Feeding

Cerithium ebumeum was fed in captivity on local
algae and detritus. It was frequently observed eating
complex algal mats, detritus, and the epiphytic algae
on Thalassia leaves. Examination of stomach contents
revealed detritus, fine sand grains, diatoms, blue-green
algae such as Anacystis aeryginosa and Mirocoleus
lyngbyaceus, and the green algae Enteromorpha and
Chaetomorpha. Fecal pellets also contained tlie above
material and were heavily invested with mucus.

Associations and Predators

Cerithium ebumeum is occasionally found with C
muscarum In the Bear Cut population, the former
often has its shell covered with filamentous green
algae. The young of Crepidula fomicata are
frequently attached to the siphonal canal of C.
ebumeum (36% of the Bear Cut population).

The prosobranch snails, Cymatium nicobaricum
and Fascioloria tulipa were observed eating C.

ebumeum Many drilled shells were found indicating
predation by naticid or muricid snails. Crabs such as
Callinectes sapidus and Calappa flammea were also
observed eating C ebumeum Randall (1967) found
C ebumeum in the stomachs of the blenny,
Labrisomus nuchipinnis, the puffer, Diodon holo-
canthus, and the porcupine fish, Diodon hystrix.
Predation by rays is also suspected.

Growth

Cerithium ebumeum has an indirect development
(Houbrick, 1970), but due to difficulties in raising
the pelagic larvae, it is unknown how long the
planktonic stage is maintained. Judging from the
small larval sheUs, and the well-developed velum and
cilia, the planktonic stage may be lengthy. Fretter
and Graham (1962) have indicated that in species
such as Cerithium, where the adult shell has a tall
spire, there is a fairly long pelagic phase.

I'll''' I'll 'III,

JJASONDJ FMAMJJ ASON
MONTHS OF YEAR

Fig. 3. Cerithium ebumeura Growth of population
expressed as a measure of shell length. Vertical lines
represent range, horizontal lines the mean, and bars,
the standard deviation. Solid bars represent months
of oviposition. Asterisk represents months of ovi-
position when other measurements were not made.

Young snails 7-8 mm in length were first found in
the population at midsummer and continued to
appear through October. Although this was 4 months
after oviposition, the young that had metamorphosed
and settled out of the plankton to a benthic
substratum may have been so small that they were
overlooked until they attained a larger size.
Therefore, the young snails that I collected may have
settled several months earlier. This would indicate

20 THE NAUTILUS

January 29. 1974

Vol. 88(1)

TABLE 1. Environmental distribution of Centhium and Rliinoclavis species.

Environments: 1. Sandy bottom 2. Rocky shore 3. Grass beds 4. Sand and rubble 5. Reef edges and fronts.
Qualitive Abundance: R=rare, P=presenl, C=common, A=abundant.

Species

Predominant

Plant
Associations

Intertidal Zone
MHW MIL MI.W

Sub tidal
Zone

Locale

Author

Chaetomorpha
Gracilaria
C. lutosum Hypnea
Halophila
Enteromorpha
Tfialassia

1,2,R 1,2,A 1,2,A 1,P

Florida This study

Jamaica Jackson, 1972

Tlialassia
C. muscarum Halodule

Syringodium

3,R

3, A

Florida

Tliis study
Jackson, 1972

Puerto Rico

Warmke &

2,C;3,P;

Almodovar,

4,C

Florida

1963;
Arnow et al.,
This study

Hypnea
C. litteratum Ceramium
Dictyota
Halmeda

Laurencia
C. eburneum Dictyota
Padina
Tlialassia

C. nodulosum Porolithon

Lithophyllum
Polysiphonia

3,P

3,C

5,P

5,C
5,P

Warmke &
Puerto Rico Almodovar,

1963;
Arnow ex^ ah

1963;
This study

C. guinaicum

4,C

Florida

This study

Enteromorpha
C. atratum Gracilaria

- 4,P

4,A;1,C

Florida

This study

Eniwetok Tliis study
Seychelles Taylor, 1968

Vol. 88(1)

THE NAUTILUS

Species

Predominant

Plant
Associations

Intcrtidal Zone
MHW MTL MLW

Sub tidal
Zone

Local

Author

C. columna

4,C
3,P;4,P

Eniwetok This study;
Seychelles Taylor, 1968

C. morum Gracilaria
Thalassia
Enteromorpha

Enhalus
Thalassia
C. rostratum Syringodium
Halophila
Cymodocea

2,A;
3,P

2,A
2,A

3,4

Seychelles Taylor, 1968;
Eniwetok This study
Aldabra Taylor, 1971

C. piperitum -

. . .

4,P

Seychelles

Taylor, 1968

C. echinatum -

. . .

4,R

4,A

Hawaii
Seychelles

This study;
Taylor, 1968

C. sejunctum Jania

2,A 2,P -

Eniwetok

This study

C. alveolus Jania

- 2,A -

Eniwetok

This study

C. articulatum -

- - -

3,P;5,C

Seychelles

Taylor, 1968

Aldabra Price, 1971

Rhinoclavis
asper

1,C
3,C;4,C

Eniwetok This study;
Seychelles Taylor, 1968

R. fasciatus

1,C

Eniwetok This study

R. pharos

Eniwetok This study

R. sinensis

4,C;5,P

Eniwetok This study
Hawaii

THE NAUTILUS

January 29, 1974

Vol. 88(1)

that a possible pelagic period of 2-3 months. After
the larvae settled, growth was rapid; the young snails
observed in October had reached an adult size by the
end of November. If one allows a month between
settling and the first observation of young snails, it
would take about 2 months for newly settled snails to
reach a mature size. New growth, indicated by the
presence of fresh whorls and thin apertural hps,
occurred from July through November. Growth
statistics for the entire sampling period are
summarized in figure 3. Population size, in numbers,
was lowest during the summer months, indicating
that after the spawning period many of the adults
died. The new generation showed up in late summer
and by eariy winter the population size had
considerably increased. It is thus probable that the
Ufe span of this population of C. ebumeum is about 1
year (Fig. 3).

ECOLOGY OF CERITHIUM ATRATUM

Habitat

This species lives in habitats of considerable
ecological diversity. It has been collected in shallow,
sandy bottoms and dredged from deeper waters in the
open sea. It may be found on limestone substratum,
areas of rubble, sand, or in Thalassia.

The collecting site at which C. atratum was studied
is located at Dunedin, Florida, along St. Joseph
Sound. The population was found on the north side
of the causeway that runs to Honeymoon Island.
Tides here range about 1 m and the causeway shore is
subject to frequent wave action. Average water
temperature was 26.7°C, ranging from 17°C in
January 1969, to 42°C in June 1969. Mean salinity
was 34.6°/oowith a low of 31"/°° in June 1969, and
a higli of 38°/°° in July 1969. As in all shallow water
environments, salinity is subject to sudden change by
runoff from heavy rains. The bottom of the shallow
portions of St. Joseph Sound is covered with
Thalassia. Along the causeway, the bottom is
irregular, consisting of rubble dredged up when the
causeway was built. The rocks are covered with
various filamentous algae and Gracilaria and Enter-
omorpha-dxe common. Winds, waves and tidal action
deposit considerable amounts of debris and detritus
throughout the intertidal zone, and the waters are
frequendy turbid.

Cerithium atratum occurs subtidally in great
numbers (150/m^) just below the low-tide mark in a
band 2 m wide bordering the causeway. It is usually

found buried in the calcareous sand around the bases
of rocks and rubble. This species was rarely seen
crawling on the substratum except during calm
periods. It does not occur beyond the rubble area.

■ lother population observed at Point of Rocks,
Sarasota, Florida, was browsing upon the
algal-covered rocks on a rocky subtidal shelf. In
Sarasota Bay, I found C. atratum crawling subtidally
on open sandy flats at low tide.
Behavior

Cerithium atratum is easy to maintain in the
laboratory. In the lab, it is a relatively inactive
animal, is usually burrowing, and moves mostly in the
dark or when disturbed. Its mode of locomotion is
monotaxic, direct. In the field, it burrowed and was
rarely found at the surface of the substratum.
Clustering on the surface was not observed, but many
individuals were often found together in the sand at
the bases of rocks. The animal exhibits a rapid
shadow response by quickly withdrawing into its
shell. Dr. Steiger (pers. commun.) claims that this
species is migratory, but no migration was observed in
the Dunedin population or at any other sites during
the study period.

Food and Feeding

In tlie aquarium, Cerithium atratum feeds inter-
mittently. After periods of starvation it is able to
detect the presence of fresh algae and detritus placed
in the aquarium and will immediately emerge from
the sand and begin feeding. Feeding also occurs
during the night. Stomach contents reveal many
coarse sand grains, detritus, crustacean appendages,
diatoms, blue-green algae and other debris. Enter-
omorpha and unidentified evaculated algal cells were
also found. In captivity, C atratum fed upon the
detritus on the bottom of the aquarium, on decaying
Thalassia and the alga, Enteromorpha.

Associations and Predators

The potamidid snail, Batillaria minima, is found
just above the upper limits of the distribution of C
atratum and extends upwards to the splash zone. No
mixing between the two species was seen, (although
they appear to play the same trophic role in tlieir
respective zones). Cerithium atratum is frequently
covered with Enteromorpha, bryozoans, barnacles,
and young oysters. It is often parasitized by
annulated rediae which give rise to fork-tailed
strigeata-Uke cercariae.

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Predators include the carnivorous snails,
Plcuroplnca gigantca, Fasciolaria himteria, Busycon
contnirhini and Mclongena corDiia. The crab,
Menippe, was also seen eating C. atratun Off-shore,
C. atratum is frequently found in the stomach of the
starfish Astropectcn articulatus (W. Lyons, pers.
commun.).

Growth

Although samples of this population were collected
monthly over a period of two and one half years, no
significant changes in the mean length of individuals
in the population occurred. Oviposition occurs from
March througli July and development is indirect. A
few young snails were found in November, December,
and January of 1970, but despite thorough screening
of the sediments, no other juveniles were en-
countered. Consequently, it is not possible to
estimate the growth rate of this population.

ECOLOGY OF OTHER SPECIES

Other, less detailed, observations were made on
Cerithium species in Florida, the Caribbean, and in
the Pacific.

In Florida and the Caribbean, populations of
Cerithium litteratum (Born) occur just at the low tide
mark and subtidally. They are usually associated with
algal-covered rocks and rubble found near the shore
hne and in shallow water patch reefs. 1 observed a
large subtidal population of C. litteratum on an
algal-covered rocky bottom off of Boca Raton,
Florida. Stomach contents of members of this
population contained detritus and the algae Eiiter-
omorpha and Cliaetomorpha.

Dead snails with drilled shells were common at
Boca Raton indicating predation of boring gastro-
pods. Randall (1967) found C. litteratum in the
stomach of the puffer fish, Diodon holacanthus.

Cerithium guinaicum Philippi, 1849, /=C.
auricoma Schwengel] ' occurs subtidally (1-3 m) in
southern Florida and throughout the Caribbean under
rocks and in the sandy pockets associated with reef
flat rubble, 1 found large populations in reef habitats
both at Sand Key, Florida and along the barrier reef
off British Honduras. Captive specimens avoid briglit
light. Stomach contents contain detritus,
Foraminifera and carbonate sediments. Many drilled
shells were seen.

In the Pacific, at Eniwetok Atoll, Marsh:ill Islands I
observed members of the genus Cerithium and the
closely related genus Rhinoelavis in the shallow water
on reef flats and lagoons. Wiens (1962) has discussed
the general ecology of atolls and the Marshall Island
group. At Eniwetok. different species of Cerithium
are separated by microhabitat, bottom types and tidal
zonation. Cerithium moms Lamarck occupies the
higher tidal zones, where it is found under rocks and
on beach rock. On the windward limestone benches,
C. alveolus Hombron & Jaquinot is found associated
with the alga, Jania at about the midtide mark,
Cerithium columna Sowerby and Rhinoclavis sinensis

C. auricoma Schwengel. 1940 is a synonym of C guinaicum.

Fig. 4. A., Cerithium atratum (Born) [Jormerty C.
floridanum Morchj B., Cerithium lutosum Menke
(formerly C. variabile C. B. Adams): C, Cerithium
eburneum Bruguiere; D., Cerithium muscarum Say.

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January 29, 1974

Vol. 88(1)

(Gmelin) are most common on the patch reefs and in
the rubble at the edges of coral reefs. Cerithium
nodulosum Bruguidre is found on rocky substratum
just shoreward of the windward reef edges.
Rhinoclavis fasciatus (Bruguiere) and R. asper
(Linnaeus) are found in sandy bottoms of leeward
lagoons.

Taylor and Lewis (1970) found four species of
Cerithium in the marine grass beds of Mahe,
Seychelles. All were algal-detritus feeders. Cerithium
rostratum Sowerby lives in grass beds in the leaves.
Cerithium moms is present in large numbers in the
sediment surface of the grass beds, in contrast to its
habitat on Eniwetok. Riiinoclavis asper is found
buried beneath the sediment on windward reefs.

The stomach contents of these Indo-Pacific species
consisted primarily of detritus, carbonate sediments
and algae. Cladophora and Chaetomorpha were found
in the stomach of C morus while the blue-green alga,
Lyngbia and the red alga, Poiysiphonia, were
common in the stomach of C nodulosum, Taylor and
Lewis (1970) observed C rostratum engulfing the
epiphytic alga, Enhahts on Seychelles.

I observed the camiverous snail, Cymatium
nicobaricum, eating Cerithium columna at Eniwetok.
The same predator eats Rhinoclavis sinensis in Hawaii
(Houbrick and Fretter, 1969). The snsA, Pleuroploca
trapezium, preys upon C. echinatum (Lamarck) in
Seychelles (Taylor and Lewis, 1968). Morula
granulata, a muricid snail, reportedly eats Hawaiian
species of Cerithium (Kohn, 1970).

DISCUSSION

The environmental distributions of members of the
genus Cerithium are summarized in Table 1. Most
species are tropical or subtropical, and temperature is
undoubtedly the primary limiting factor in their
distribution. It is difficult to derive any coherent
ecological conclusions because only four species and
their respective stations were examined in detail and
the geographic ranges of these four species are
extensive. Moreover, some species, such as C
lutosum, occur in a variety of habitats and under
differing environmental regimes. Substrate prefer-
ences of cerithiids appear to vary between soft and
hard bottom types. Most species occur on sandy
bottoms or hard bottoms with algal mats.

In terms of vertical distribution, the species most
frequently exposed during low tides in the Western
Adantic are Cerithium lutosum and C muscarum.

Cerithium lutosum, the smallest member of the genus
in the western Atlantic, occupies the highest tidal
level, close to shore, while C. ebumeum, C. atratum
and C litteratum occur subtidally. C. guinaicum lives
in the deepest zones. C atratum, C. litteratum and C.
guinaicum are the largest of the western Atlantic
species.

In the Pacific, C. morus, C. alveolus and C
sejunctum, all small species, occupy the intertidal
zone; C. morus lives in the highest tidal zone; C.
columna and C. echinatum are found subtidally; the
largest species, C. nodulosum, occurs in deeper,
subtidal zones. Thus a pattern emerges in which
species which are found intertidally are smaller than
those occuring subtidally. Jackson (1972) noted the
same phenomenon in Jamaica and suggested that
epifaunal moUusks from high stress environments
tend to be much smaller than their more stenotypic
relatives. Atapattu (1972) found that Cerithium
species in Ceylon were more abundant in sheltered
places along the coast.

In Florida C. muscarum and C lutosum are more
euryhaline than other species although C atratum is
in the brackish waters of the Intercoastal Waterway at
St. Lucie, Florida. Parker (1959) found C lutosum in
the hypersaline waters of the Laguna Madre, Texas.

Many species of Cerithium are loosely associated
with beds of marine grasses such as Tlialassia and
Ruppia. A summary of the plant and algal
associations with Cerithium species througliout the
world is given in Table 4.

All species of Cerithium that I examined are
style-bearing algal-detritus feeders. In Florida, the
Caribbean, and the Pacific, I observed several species
occuring together in the same general habitat. Kohn
(1971) has suggested that co-occurring congeners that
feed selectively on detritus tend to specialize to
different micro-habitats. This is probably true of
Cerithium species because the stomach of all
examined species are complex structures, higWy
specialized for the sorting and transport of small
particles and detrital material, indicating that partical
selection is taking place. DriscoU (1972) found that
the stomachs of the potamidids, Batillaria zonalis and
Cerithidea califomica, were specialized to selectively
transport and digest a continuous supply of detritus
by means of complex ridges, grooves and ciliary
currents. Batillaria and Cerithidea species are related
style-bearing mesogastropods of the super-family
Cerithicaeae. The role of detritus in the nutrition of

Vol. 88(1)

THE NAUTILUS

marine detritus feeders has been discussed by Newell
(1965) who suggested that animals living on detritus
feed by abstracting proteins from the bodies of
microorganisms, such as bacteria that coat the silt and
organic debris, and reject the organic carbon
compounds with the feces. Odum(1971) pointed out
that detritus feeders obtain some of their energy
directly from plant material, most of it secondarily
from microorganisms, and some tertiarily through
carnivores, such as protozoa and small invertebrates. I
was unable to distinguish what the sympatric species
of Cerithium selectively ate and consequendy their
exact ecological niches in the trophic scheme remain
unknown. It is probable that competition is avoided
and ecological niches determined by particle selection
in the complex sorting mechanisms of the stomach.
But as Odum (1971) stated, apportioning the energy
sources utilized by detritus feeders at the individual
and species level presents a difficult technical
problem which has not been solved.

I observed many Cerithium species engulfing algae
as well as detritus, especially the small epiphytic algae
associated with blades of marine grasses. Feeding
occurs continuously as in most mollusks possessing a
style (Graham, 1939). A review of style-bearing
gastropods and their feeding occurs in Driscoll
(1972). The abundance of detritus and algae in
shallow water habitats probably reduces competition
for food among sympatric members of the genus
Cerithium

The reproductive biology of the genus Cerithium
has already been discussed (Houbrick, 1970; 1971;
1973, in press).

Cerithium muscarum, C. lutosum, C. ebunieum,
and C. atratum exhibit a definite seasonal repro-
ductive activity. Oviposition occurs in these species
from winter througli spring. Young snails appear in
the populations during the summer and eady autumn.

1 was unsuccessful in attempts to rear newly
hatched snails to adulthood, but size frequency data
along with qualitative observations indicate that it
takes about one year to attain maturity. Raeihle
(1968) was successful in rearing larvae of C hitosum
from the Florida Keys to adulthood. She found that
the larval shells were less than 1 mm in length 5
weeks after hatching; at 1 2 weeks they had reached
1.3 mm and by 13 months they were 8-11 mm in
length and were reproductively mature, having
spawned 13 months after the time of hatching. These
findings are compatible with my size-frequency data

which indicate a life-span of one year.

It is more difficult to determine the growth rates
of Cerithium species with pelagic life histories than
those with direct life histories because the time spent
in the plankton before settling is unknown, and one is
never sure if the juveniles found in a population are
products of the spawn of that particular population.
The results of this study indicate that the Florida
populations of C. lutosum, C. muscarum and possibly
C ebunieum grow from juvenile stages to adult stages
in a few months, and that their life spans last
approximately one year; however, spawning and
growth may vary in other populations of Cerithium
species depending upon their geographic distribution.
Lewis et al. (1969) found different rates of growth
for the same species of mollusks, depending upon
their latitudinal distribution in the Caribbean. They
also mentioned that microclimatic differences are
equally as important as latitudinal ones. The annual
cycles of the species studied indicate that the
majority of the adult populations die after spawning.
Vohra (1970) observed the same phenomenon in
Cerithidea cingulata.

Horizontal movement, migration and seasonal
recruitment from other areas were not observed in
the populations of C. lutosum and C. muscarum;
despite the fact that these species have a direct
development, it is possible that eggs on marine grasses
may drift from one locality to another. In species
with indirect development, recruitment from other
populations is probable. More detailed studies may
reveal subde tidal or season migrations in Cerithium
species. Mark and recapture experiments with
Cerithium stercusmuscanim indicate a migratory
pattern due to positive phototaxis to the rising sun
(Burch and Burch, 1970). Vohra (1965, 1970) found
that the potamidids, Pyrazus ebenitjus and Cerithidea
cingulata, migrated with tides and seasons, respec-
tively. Horizontal and vertical migrations may be
correlated with drainage and presence of detrital food
as well as with spawning behavior. A discussion of
these factors may be found in Vohra (1970).

1 observed segregation between older (larger) and
younger (smaller) individuals of C lutosum Older
specimens were found further upshore while the
younger ones occurred just subtidally. A similar
segregation pattern was also noticed by Vohra (1970)
in Pyrazus ebeninus.

Some clustering of Cerithium lutosum, C. morum,
C. alveolus and C sejunctum occurs at low tides.

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January 29. 1974

Vol. 88(1)

Moulton (1962) believed that this phenomenon is an
adaptation of Ceriihium to drying conditions and
higli temperatures on tropical beaches and postulated
that clustering is a homeostalic mechanism. He
suggested that Ccrithhim possesses a hydrostatic
mechanism which helps to determine whether the
animals shall be clustered or dispersed. Fischer (1966)
added the idea that adhesion to a preferable
substratum may also be a factor in aggregation.

The potamidid snail, Batillaria minima was found
closely associated with most of the Ccrithiiim species
in Florida. Batillaria appears to fulfill the same
trophic function as Cerithium only at a higlier level in
the tidal /one. Its close association and resemblance
to Cerithium lutosum has led to confusion between
the two species (Abbott, 1954), and to erroneous
reports of egg laying, etc. At Port Everglades, Bear
Cut, and Pigeon Key, Florida, 1 observed the two
species overlapping in a minor degree in their vertical
distribution. During periods of high seas they are
frequently mixed together.

Considering the great numbers of snails observed in
the study areas, it is surprising that more predators of
Cerithium were not seen. Most of the predators listed
in this study were observed infrequently and only
account for minimal mortality. Fish may prove to be
the main predators of the species with very large
populations. A more quantitative study of predation
is needed in order to elucidate the exact position of
Cerithium species in the trophic structure of the
shallow-water communities they inhabit.

ACKNOWLEDGEMENTS

This paper forms part of a series dealing with the
biology of the genus Cerithium Much of the work
was done as part of a PhD program at the University
of South Florida at Tampa under the direction of Dr.
Joseph L. Simon. I am indebted to him for his help,
guidance and criticism during tlie project. My thanks
are also due to the members of my committee and
the faculty of the Department of Biology. My
appreciation is extended to Cathy Lamb who kindly
assisted in the proof-reading of the manuscript. My
thanks are also extended to Sally Kaicher who kindly
took the photographs. Support for the work at
Eniwetok was provided by the U.S. Atomic Energy
Commission througli the University of Hawaii and the
Eniwetok Marine Biological Laboratory.

LITERATURE CITED

Atapattu, D. H. 1972. Littoral moUusks of Ceylon.
Mar. Biol. 16: 1. SO- 164.

Burch, T. A. and B. L. Burch 1970. Dispersion of
Cerithium stercusmuscarum on a tidal sand flat.
The Echo, 1970: 18.

Dragovich, A. and J. Kelly 1964. Ecological
observations of macro-invertebrates in Tampa Bay,
Florida. Bull. Mar. Sci. 14(4): 74-102.

DriscoUe, A. L. 1972. Structure and function of the
alimentary tract of Batillaria zonalis and
Ceriihidea califoniica, stylebearing mesogas-
tropods. The Veliger 14(4): 375-385.

Fischer, P. 1966. Disposition gr^gaire chez un
Cerithium Indo-Pacifique. Jour. Conchyl. Paris.
105:49-52.

Fretter, V. and A. Graliam 1962. British Prosobranch
MoUusks. Ray Society, London. 755 p.

Graham, A. 1939. On the Structure of the
Alimentary Canal of style-bearing Prosobranchs.
Proc. Zool. Soc. London (Ser B.) 109: 75-1 1 2.

Graham, A. 1955. MoUuscan diets. Proc. Mai. Soc.
London 31: 144-1.59.

Houbrick, J. R. 1970. Reproduction and develop-
ment in Florida Cerithium Amer. Mai. Union Inc.,
Ann. Rep. 1970:74.

Houbrick, J. R. 1971. Some aspects of the anatomy,
reproduction, and eady development of Cerithium
nodulosum Brugui^re (Gastropoda, Prosobranchia).
Pacific Sci. 25(4): 560-565.

Houbrick, J. R. 1974. Studies on the reproductive
biology of the genus Cerithium in the Western
Atlantic. BuU. Mar. Sci. (in press).

Houbrick, J. R. and V. Fretter 1969. Some aspects of
the functional morphology and biology of
Cymatium and Bursa. Proc. Mai. Soc. London. 38:
415-429.

Hutton, R. F. and F. Sogandares-Bemal I960. Studies
on helminth parasites from the coast of Florida, II.
Digenetic trematodes from shore birds of the west
coast of Florida. Bull. Mar. Sci. Gulf and Carib.
10(1): 40- .54.

Jackson. J. 1972. The ecology of the mollusks of
Thalassia communities in Jamaica, West Indies. II.
Molluscan population variability along an environ-
mental stress gradient. Mai. Biol. 14(4): 304-337.

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THE NAUTILUS

Kohn, A. J. 1970. Food habits of the gastropod A/;7ra

Uttcrata Lamarck: Relation to trophic structure of

the intertidal marine bench community in Hawaii.

Pacific Sci. 24(4): 483-486.
Lewis. J. B., F. Axelsen. L Goodbody, C. Page. G.

Chislett, and M. Choudhoury 1969. Latitudinal

differences in growth rates of some intertidal

mollusks in the Caribbean. Mar. Sci. Manuscript.

Rep. 1 2, McGiU Univ., Toronto. 89 p.
McNulty, J. K. 1962. Level sea bottom communities

in Biscayne Bay and neighboring areas. Bull. Mar.

Sci. Gulf and Carib. 12(2): 204-233.
Moore, H. B. 1958. Marine Ecology, Wiley and Sons,

New York. 493 p.
Mornll, J. B. and F. G. W. Olson 1955. Literature

survey of the Biscayne Bay area. Fla. State Univ.

Oceanogr. Inst. Mimeo. Rpt. to U.S. Navy Hydro.

Office. 1 34 p.
Moulton, J. M. 1962. Intertidal clustering of an

Australian gastropod. BioL Bull. 123(1): 170-178.
Newell, R. 1965. The role of detritus in the nutrition

of the marine deposit feeders, the prosobranch

HydnMa itlvae and the bivalve, Macoma halthica.

Zool. Soc. (London), Proc. 144: 25-45.
Odum, E. P. 1971. Fundamentals of Ecology, 3rd

Ed., W. B. Saunders Co., Philadelphia. 574 p.
Parker, R. H. 1959. Macro-invertebrate assemblages of

central Texas coastal bays and Laguna Madre. Bull.

BOOK

AMERICAN MALACOLOGISTS. (editor) R. Tucker
Abbott. First Edition, iv + 494 pages. American
Malacologists, 6314 Waterway Drive, Falls Church,
Virginia 22044. Hardbound, $12.50.

This is the first attempt to bring together the
biographical sketches of all American malacologists,
both past and present. Its scope is wide, as it covers
both the professional and amateur students interested
in any phase of the mollusca.

These personal sketches cover a wide spectrum of
facts, not only the vital statistics, but in addition, the
interests, travels, publications and other data of much
historical value. Many of the deceased persons
covered in the book built up important shell
collections. A large number of these collections have
been given or sold to museums. Their present location
is of considerable value to historians and research
workers as a source of much informative data.

Amer. Assoc. Petrol. Geologists. 43(9): 2100-2166.
Raeihle. D. 1968. Notes on captive Ccrithium
variabilc and Mitra floridana. Amer. Mai. Union,
Inc. Ann. Rep. 1968: 35-36.

Steel, R. and J. Torrie I960. Principles and
procedures of statistics. McGraw-Hill, New York.
481 p.

Tabb, D. C, D. L. Dubrow, and B. Manning 1962.
The ecology of northern Florida Bay and adjacent
estuaries. State of Fla. Board of Conserv. Tech.
Ser. 39: 81 p.

Taylor, J. 1968. Coral reef and associated inver-
tebrate communities (mainly molluscan) around
Mahe, Seychelles. Phil. Trans. Roy. Soc. London
254B: 129-206. 5 pis.

Taylor, J. and M. S. Lewis 1970. The flora, fauna and
sediments of the marine grass beds of Mahe,
Seychelles. Journal. Nat. Hist. 4: 199-220.

Vohra, F. C. 1965. Ecology of intertidal Zostera flats
of Moreton Bay. Ph.D. Thesis, University of
Queensland.

Vohra, F. C. 1970. Some studies on Cerithidea
cingidata (Gmelin 1790) on a Singapore sandy
shore. Proc. Mai. Soc. London, 39(2/3): 187-201.

Wilbur. K. M. and G. Owen 1964. Growth, pp.
211-242, In K. M. Wilbur and C. M. Yonge,
Physiology of Mollusca. Academic Press, N.Y.

REVIEW

A feature of considerable importance, in addition
to the biographies of 539 past workers, is a list of 420
persons about whom little is known other than their
names. These people have had a particular interest in
mollusks, and most of them at one time or another
reached die printed page either as authors or
collectors. Dr. Abbott hopes that interested persons
may be able to add new data or give references where
such information may be found. Completion of this
section will be a major contribution to the history of
our science.

Analyses have been made of all living malacologists
as to their geographic location, their individual fields
of research and endeavor, and their main occupation
if they are not professional malacologists. Among our
reference books, this will be one of the most
frequently consulted.

William J. Clench

26 Rowena Street

Dorchester, Mass. 02124

THE NAUTILUS

January 29. 1974

Vol. 88(1)

ON A SINISTRAL SPECIMEN OF LIGVUS VIRGINEUS
(WITH ADDITIONAL REMARKS ON THE GENUS LIGLVS)

Morris K. Jacobson and William E. Old, Jr.

American Museum of N;itural History
New York, New York 10024

Sinistral specimens of Ligitus virgineus
(Linnaeus) from Hispaniola are exceedingly rare.
Pilsbry (1899: 163-164) listed five records known
up to that time, citing illustrations for three of
lliem. However, the figures published by Klister &
Pfeiffer (pi. 14, fig. 9, 10) are copies of those of
Chemnitz (1788, pi. 173, figs. 1682-1683) so that
up to the present, sinistral specimens have been
figured only by Favanne (1780, pi. 65, fig. G4)
and Qiemnitz (1788).

The specimen here illustrated, therefore, is of
interest. Tire shell was presented to The Ainerican
Museum by Mr. Burton Anderson of Dania,
Rorida, who found it, together with another such
specimen, in a shipment of L. virgineus from
Haiti. No other data are available.

The present specimen measures 33 mm in
height, 18.5 mm in width, aperture height 12 mm.
The color bands are as follows: a yellow band
below the suture, a purplish-black band, a slate
blue one, and a rose one at the periphery. There
is a faint yellow band encircling the base.

A word might be added here about the rarity
of this type of teratology in the genus Ligitus.
Pilsbry (1946: 39) guessed that it occurs among L.
fasciatus (Miiller) in Rorida in the order of one in
10,000 and cited the testimony of Mr. R. F.
Deckert who knew of only 9 sinistral shells. W. J.
Clench (personal communication) stated that he
has examined perhaps 60,000 specimens of Liguus
without having encountered a single sinistral spec-
imen.

Dautzenberg (1914; 51) commented on the
relative abundance of reported sinistral shells
among Helix pomatia Linnaeus and H. aspersa
Miiller as compared to other pulmonale species.
He concluded that this is probably due to the fact
that the former were collected - even bred - in
vast numbers for culinary purposes and thus many
more shells came to the attention of collectors.
This would also partly explain the scarcity of
similar shells in the genus Liguus.

Two other mmor comments can be made.
Dautzenberg (1914) presented a list of all species
in which dextral and sinistral teratological speci-
mens were reported, but strangely included Liguus
poeyanus (Pfeiffer) (=vittatus Swainson) of Cuba, a
species which like Amphidwmus from southeastern
Asia, appears ambidextrously in most populations.
Zilch (1960: 518) erroneously included Cozumel
Island as lying within the range of Liguus
(Oxystwmbusj. This subgenus is limited to south-
ern Florida, Cuba, and the Isle of Pines - which
Zilch transcribes in the Portuguese fashion as 'Isla
dos Pinhos.'

LITERATURE CITED

Chemnitz, J. H. 1788. Neues Systematisches

Conchylien-Cabinet, Nurnberg, 10: 1-376, pis.

137-173.
Dautzenberg, P. 1914. [Sinistrosites et dextrosites

teratologiques chez les moUusques gasteropods] .

Bull. Soc. Zool. de la France 39: 50-59.

FIGS. 1 and 2. Liguus virgineus from Haiti Lej..
a specimen of the dextral or normal form, 32 mm.
in height. Right. Sinistral specimen, 33 mm, in
height. (Photos courtesy of The American Museum
of Natural History).

Vol. 88(1) THE NAUTILUS 29

ftvanne de Montcervelle. 1780. 3rd Edition of Land Mollusca of North America (North of

Desallier D'Argenville's La Conchyliologie. Paris, Mexico). Acad. Nat. Sci. Philadelphia, Mono-

2 vols, and atlas. graph 3, 2 (1): 37-102, figs. 20-50 + colored

Kiister, H. C. and L Pfeiffer [1840] -1857- [1865]. frontispiece (genus Liguus)

Systematisches Conchylien-Cabinet, (1) 13: Smith, E. A. & H. W. England. 1937. Jour. Soc.

281-304 [pi. 14 appeared in 1843, fide Smith Bibliog. Nat. Hist. 1: 89-99.

and England, 1937.] Zilch, A. 1960. Gastropoda, pt. 2, Euthyneura

Pilsbry, H. A. 1899. Manual of Conchology (2) [in] Handbuch der Paliiozoologie, Berlin (6) 3:

12: 160-175, pis. 55-60 (genus Liguus). 1946. 517-518, figs. 1803-1805 (genus /./gw«x).

THE CHROMOSOME NUMBER OF EUGLANDINA ROSEA
(STYLOMMATOPHORA: OLEACINIDAE)

Edward M. Stem

Department of Zoology and Physiology
Louisiana State University
Baton Rouge, La. 70803

ABSTRACT

No chromosome numbers have been reported for members of the Stylom-
matophoran family Oleacinidae. Examination of chromosome spreads for Euglandina
rosea (Fentssacj revealed a haploid number of n=29. It has been suggested that
higher chromosome numbers may be correlated with phylogenetically more advanced
or morphologically specialized Euthyneuran snails. The high chromosome number
obtained here substantiates this, even in the light of the extremely conservative
nature of chromosome numbers.

^-# • •^

Chromosome numbers are known for less than
0.5% of the species of recent mollusks, and none
has been reported for members of the Stylom-
matophoran family Oleacinidae. Several individuals
of Euglandina rosea (Ferussac) were collected in
January, 1973, from under moist debris along the
Mississippi River levee. Port Allen, West Baton
Rouge Parish, Louisiana. The snails were injected
directly through the shell near the apical whorl
with .15cc of Velban (Img/ml concentration) and
returned to their container. They were sacrificed
approximately 16 hours later and the ovotestis
removed. Meiotic chromosome squashes were pre-
pared using an acetic-orcein squash technique as
described by McPhail and Jones (1966).

Six spreads of E. rosea were examined and
revealed a haploid number of n=29 (Fig. 1). 1^ •■

Morphologically, with regard to the modified

radular teeth, and ecologically, as evident by its FIG. 1. Meiotic chromosomes of Eu^andim rosea,

carnivorous diet, E. rosea might be considered a Scale line = 5 micra.

January 29, 1974

Vol. 88 (1)

specialized species. Burch (1965), Patterson (1969
and 1971) and others have suggested that higlier
chromosome numbers may be correlated with
phylogenetically more advanced or morphologically
specialized Euthyneuran snails. Conversely, lower
chromosome numbers are found in the more
"primitive" groups. Tiie infraordcr Hoiopoda con-
tains some relatively morphologically specialized
groups of land snails, including the active, rapa-
cious members of the family Oleacinidae. Haploid
chromosome numbers for the Hoiopoda range
from n=21 to n=3l. The high hapkiid chromosome
number (n=29) of E. rosea seems to substantiate
the above contention.

The chromosome number for E. rosea is similar
to those found for other species in the suborder
Signiurcthra, which is ihouglit to be the most
advanced Stylommatophoran group with a mean
chromosome number of 28.6 and a mode of 29
(Patterson, 1971). Ranier (1967) stated that, in
general, relationships suggested by cytologjcal
studies have correlated well with the modern
classification of the Stylommatophora. However,
because of (1) the extremely conservative nature
of chromosome numbers, even at the subordinal
level as noted above, and (2) the number of
exceptions, as pointed out by Ranier (1967) in
the Helicidae, a broad statement may not yet be

justified. Nevertheless, when used in conjunction
with other techniques, cylolaxonomy represents a
valuable tool that may be used by the systematist
in an attempt to confirm or question phylogenetic
relationships previously based solely upon morph-
ological and/or anatomical features.

ACKNOWLEDGMENT

Special thanks are given Dr. J. B. Burch for his
comments concerning this paper.

LITERATURE CITED

Burch, J. B. 1965. Chromosome numbers and

systematics in euthyneuran snails. Proc. First

Europ. malacol. Congr., 1962, p. 215-241.
McPhail, J. D. and R. L. Jones. A simple

technique for obtaining chromosomes from

teleost fishes. J. Fish Res. Bd. Canada 23:

767-769.
Patterson, C. M. 1969. Chromosomes of molluscs.

Proc. Symp. Moll., Mar. Biol. Assoc. India

1969: 635-686.
Patterson, C, M, 1971. Taxonomic studies of the

land snail family Succineidae. Malacol. Rev. 4:

131-202.
Ranier. M. 1967. Chromosomenuntersuchungen an

Gastropoden (Stylommatophora). Malacologia 5:

341-373.

BOOK REVIEW

SEASHELL PARADE. By A. Gordon Melvin. 369
pp., 74 ph., 1 in color. Charles E. Tut tie, Co.,
Rutland, Vt. 0570 L Hardback, $11.50.

For shell collectors who enjoy reading about shells
and learning more about their usefulness and interest
to man, this book will supply many pleasant hours.
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gists, but this project is now superseded by the rather
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national register. "American Malacologists. "

An excellent chapter gives a panoramic treatment
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interest to shellers. Curiously, however, the author
has evidently forgotten that the writer of the famous
children's book. Captain January, was Mrs. Laura E.
Howe Richards, and not California's Julia Ellen
Rogers, author of The Shell Book.

R. Tucker Abbott

du Pont Chair of Malacology

Delaware Museum of Natural History

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THE
NAUTILUS

Volume 88, number 2 — April 1974

CONTENTS

Harald A. Rehder and Clifton S. Weaver

A New Species of Volutocorbis from South Africa 31

Harald A. Rehder

On the Genus Volutocorbis with Descriptions of Two New Species from

South Africa 33

Don Mauer, Les Watling and Glenn Aprill

The Distribution and Ecology of Common Marine and Estuarine Pelecypods

in the Delaware Bay Area 38

Glenn A. Long

Frog Motifs on Archaeological Mollusks of Hohokam and Mogollon Indian

Cultures 47

Donald W. Kaufman

Additional Record tor Mesodon leatherwoodi (Pulmonata: Polygyridae) 51

Alice Denison Barlow

New Florida Records tor Hypselodoris edenticulata (Nudibranchia:

Dorididae) 52

M. Ellen Crovo

Further Notes and Corrections Concerning the Spawn of Florida

Cyphoma (Ovulidae) 53

Dominique A. Bucci

Viviparus malleatus in Montreal, Canada 55

John N. Rinne

The Introduced Asiatic Clam, Corbicula, in Central Arizona Reservoirs 56

Stanley V. Margolis and Robert E. Carver

Microstructure of Chalky Deposits Found in Shells of the Oyster,

Crassostrea uirginica 62

Fred B. Blood and Marceile B. Riddick

Unionidae of the Pamunkey River System, Virginia 65

Lowell L. Getz

Arion subfuscus in the Vicinity of Washington, D.C 66

Allyn G. Smith

Galapagos Bulimulids: A Taxonomic Correction 67

Joan Antill

Another Fossil Ovoviviparous Turritella 67

News and Errata 68

Book Reviews

(of) Louie Marincovich, 37; Arthur H. Clarke 45

III

Marine MoUuscan Genera
of Western North America

An Illustrated Key

A. Myra Keen & Eugene Coan

Second Edition. First published in 1963, this
Key has become the standard reference work
and handbook in its field. This second edition
has been completely revised and reset, the page
size has been reduced to make the book more
portable, and the illustrations have been pro-
vided with additional information to aid the
novice in making easy identification. The text of
the Keys takes account of the most recent
nomenclatural changes and introductions of
genera to the region, and an entirely new section
has been added to identify the species used for
each illustration in the Keys. The Systematic
Lists, Notes on Ranges and Habitats, Glossary,
and Bibliography have been greatly expanded
and revised; and the Systematic Lists now in-
clude the many non-shelled genera to be found
on the Pacific Coast. $8.75

Stanford University Press

Vol. 88 (2)

THE NAUTILUS

ANEW SPECIES OF VOLUTOCORBIS FROM SOUTH AFRICA

Harald A. Rehder

National Museum of Natural History

Smithsonian Institution, Washington, D. C. 20560

and

Clifton S. Weaver

1038 Mokulua Drive

Kailua, Hawaii 96734

Some years ago Mrs. Helen Boswell, of
Valhalla, Transvaal, South Africa, sent speci-
mens of an apparently new species of
Volutocorbis to the junior author, who
prepared a preliminary description. Somewhat
later Mrs. Boswell sent further specimens of
the same species to the senior author. In view
of this we have decided to prepare this paper
jointly.

In addition to expressing our appreciation
to Mrs. Boswell for her continuing coopera-
tion, we also wish to thank Mr. Michael
Meyer, of Durban North, Natal, and Mr.
Kenneth J. Fuller, of Lambton, Germiston,
Transvaal, both of whom have sent us
material of the new species. A fine specimen,
which has been made the holotype, was sent
us recently by Mr. Richard N. Kilburn, of the
Natal Museum, Pietermaritzburg, to whom we
express our thanks.

After this paper was completed two further
specimens were loaned to us by Mr. William
E. Old, Jr. of the American Museum of
Natural History. These specimens, found
attached to Xenophora pallidula Reeve, were

received from Mr. C. P. Fernandes of
Lourengo Marques, Mozambique. They repre-
sent an extension of range, and so have been
included in this paper. Our grateful thanks to
Mr. Old for allowing us to examine this
material.

Volutocorbis semirugata

Rehder and Weaver, new species

Figs. 1-8

Diagnosis — Shell of medium size, 33.0 to
55.3 mm (VA to 2V4 inches) in length, rather
shiny, axial ribs absent on body whorl or if
present found only below angulate shoulder
as low broad, rather obscure folds, especially
in early portion of whorl. Outer lip very much
thickened and reflected, posteriorly ascendant
on penultimate whorl, sometimes obscurely
denticulate, especially in gerontic specimens.
Resembles V. gilchristi (Sowerby, 1902) but
is larger, with weaker sculpture on last whorl,
and with sloping shoulder, not canaliculate
subsuturally.

Range — From off central Natal, South
Africa, between Durban and the mouth of the

FIGS. 1-8. Volutocorbis semirugata Rehder
and Weaver, new species: Figs. 1, 5, holotype.
Natal Museum Moll. 9939, 45.1 mm. in
length. FIGS. 2, 6, paratype #1, USNM

709349, 54.3 mm. in length. FIGS. 3, 7,
paratype #3, Boswell Colin., 47.9 mm. in
length. FIGS. 4, 8, paratype #7, Boswell
Colin., 38 mm. in length.

32 THE NAUTILUS

April 30, 1974

Vol. 88(2)

Tugela River, to off Louren90 Marques,
Mozambique, in 100 to 280 fathoms.

Description — Shell of medium size, 33.0
to 55.3 mm (I'/i to 2'/^ inches) in length,
elongately ovate. Ground color pale yellow to
straw color or light grayish yellowish brown,
sometimes bluish gray on the body whorl;
fresh specimens vnth interrupted (occasion-
ally continuous) axial streaks of reddish
browTi or with spiral bands of interrupted
blotches of reddish brown. Protoconch
mammillate, with 2V4 smooth, rounded, pale
straw-color whorls, initial whorl slightly
tilted. Early postnuclear whorls with low,
rather distant axial ribs that show a small
node below the suture, and a somewhat
larger one on the shoulder, with an obscure
one below, or rarely above. The subsutural
series may increase in strength for one or
more whorls and then decrease, or the series
may rapidly become obscure, ridgelike, and in
the last whorl disappear; the shoulder knobs
are strongest on the antepenultimate and
penultimate whorls but become weaker on
the last whorl, being present either as one or
two unequal low ridges or a series of low
nodes. The lower half of the body whorl is
strongly marked by spiral grooves, which
towards the base form angulate ridges.
Aperture long, narrow, slightly arcuate, the
anterior canal rather narrow and at a slight
angle to the axis of the aperture. Outer lip
broad, posteriorly ascending halfway up on
the penultimate whorl, generally thickened
internally and externally, where it forms a
stout varix; noticeably denticulate at inner
edge. Parietal lip meeting in a broad angle
with the columellar lip which is usually made
slightly arcuate by reason of the columellar
pad bearing the numerous plaits; plaits on
columellar pad normally 9 to 11 of varying
strength, separated from basal fold by a
pronounced groove. A rather broad, white

callus, thick on the columellar area, extends
from the inner lip over half of the ventral
surface of the body whorl.

Material - Holotype: SE of the Bluff,
Durban, in 120 fathoms; collected by G.
Scott, August 1872. Natal Museum, Mollusca
No. 9939.

Paratypes (see table of measurements
below): Nos. 1, 6, 10, 13: 10-20 miles off
mouth of Tugela River, in 120-150 fathoms;
Nos. 3, 4, 7: 15-20 miles off Durban, in 280
fathoms; Nos. 2, 5, 8, 9: off southern
Zululand, in deep water; Nos. 11, 12: 10
miles NE of Inhaca Island, Lourengo Marques,
Mozambique, in 100 fathoms.

Measurements (mm)

length width no whorls

Holotype

(Natal Museum

Moll. 9939)

45.1

19.5

6 '4

Paratypes

(USNM 709349)

54.3

23.6

6'/2

(Fuller Colin.)

49.6

25.3

(apex worn)

ii3

(Boswell Colin.)

47.9

21.6

6'/!

(USNM 709350)

43.7

19.2

6'/4

(Visagie Colin.)

38.5

17.1

6^8

(Boswell Colin.)

36.8

17.3

6'/4

(Boswell Colin.)

38.0

17.4

eVg

(Meyer Colin.)

35.3

16.5

(Meyer Colin.)

33.0

15.5

#10

(Boswell Colin.)

55.9

22.3

#11

(AMNH 177285)

41.6

19.8

61/4

#12

(Fernandes Colin

)41.1

18.1

#13

(Boswell Colin.)

on Xenophora

pallidula

Reeve

Remarks — Volutocorbis semirugata is
distinguished from all previously described
species by the axial sculpture of the early
postnuclear whorls disappearing on the last
half of the body whorl leaving it smooth
except on the angulate shoulder, and on the
base where it is marked by spiral sculpture

One specimen, paratype No. 10, is a rather
thin shell, very pale yellow without spots, and
is a typically elongate with the outer lip only
moderately thickened.

Vol. 88 (2)

THE NAUTILUS

ON THE GENUS VOLUTOCORBIS WITH DESCRIPTIONS

OF TWO NEW SPECIES FROM SOUTH AFRICA

Harald A. Rehder

National Museum of Natural History
Smithsonian Institution, Washington, D. C. 20560

In the last few years I have received new
material of the genus Volutocorbis from Mrs.
Helen Boswell of Valhalla, Transvaal, South
Africa, and from Mr. Kenneth J. Fuller of
Lambton, Germiston, Transvaal. Among them
are specimens of three new species, two
described in this paper, and one described in a
previous paper in this issue of The Nautilus
(vol. 88, no. 2). In a loan of several interesting
species of marine mollusks from the Natal
coast, sent to me by Richard N. Kilburn of
the Natal Museum, Pietermaritzburg, were
specimens of two of the new species described
in these papers. To all these correspondents I
give my grateful thanks.

Darragh (1971) has questioned the
propriety of regarding this genus as distinct
from Athleta Conrad, 1853, and Volutospina
Newton, 1906. In this respect he follows the
conclusions reached by Cossmann (1909, p.
210), who suggests that Volutocorbis, Voluto-
spina and Neoathleta Bellardi, 1890, should
be considered junior synonyms of Athleta
Conrad, 1853, because he felt that in
sculptural characters and general shape there
were species that represented transitional
stages between these groups that he had at
one time considered of sectional rank. In
support of this viewpoint he cited the work of

Burnett Smith (1906) on the races of
Volutilithes petrosus Conrad, 1853.

Both Cossmann and Darragh with justice
depreciate the importance of the size and
number of whorls of the protoconch as a
basic character in classifying the Volutidae.
Cossmann complained that Dall
overemphasized the generic significance of the
nuclear whorls while ignoring the characters
of the columellar folds (Cossmann, 1907, p.
191). Earlier, Cossmann (1899, p. 101) in
discussing his classification of the Volutidae
had stressed the necessity of utilizing all
characters found in the shells.

In the process of reviewing the problem of
the proper allocation of the group Voluto-
corbis I decided to use this occasion to
reorganize and arrange the Cenozoic members
of the family Volutidae present in the
National Museum of Natural History. I had,
therefore, the opportunity of examining
hundreds of specimens from both Europe and
the United States, which I attempted to
arrange according to what I considered a
logical classification. Particular attention was
paid to the representatives of the subfamily
Athletinae. Needless to say, the conclusions
arrived at, and which I outline in the
following paragraphs, are in a sense prelim-

FIGS. 1-4 Volutocorbis nana Rehder, new
species: FIGS. 1, 3, holotype, USNM 709351,

23.5 mm. in length. FIGS. 2, 4, paratype.
Fuller Colin., 20.6 mm. in length.

34 THE NAUTILUS

April 30, 1974

Vol. 88(2)

inary, and should be considered as suggested
guideposts in future, more detailed phylo-
genetic studies similar to the excellent one
published by Fischer, Rodda, and Dietrich
(1964). It is to be hoped, however, that these
studies will involve related species and genera
from other faunal areas, on both sides of the
Atlantic.

Darragh in his study makes only occasional
references to the columellar plaits found in
members of the groups under discussion,
emphasizing primarily the characters of the
protoconch and external sculpture. I believe
that the folds on the columellar can be
utilized in arriving at a satisfactory classifica-
tion provided one considers their basic
characters and is not led astray by minor
details.

I consider Athleta Conrad, 1853, whose
type-species is Valuta rarispina Lamarck,
1811, of the Miocene of France, to be distinct
from the Volutospina — Volutocorbis
complex. The columellar folds are stouter,
with two lowermost ones equal or subequal in
strength, the upper one of the two frequently
the stronger. On opening the shell behind the
aperture three ascendant plaits are seen on the
columella, the upper one usually less promi-
nent than the other two. The early post-
nuclear whorls may be cancellate or with axial
ribs crossed by spiral grooves. The protoconch
is turbinate or mammillate with several
smooth whorls. Synonyms are Eoathleta
Gardner, 1945, and Volutovetus Pilsbry and
Olsson, 1954. Based on the figure and
description Bendeluta Fames, 1957, may also
for the time being be placed in the synonymy
oi Athleta.

The genera Volutocorbis Dall, 1890 (type-
species V. limopsis (Conrad)) and Voluto-
spina Newton, 1906 (type-species V. spinosa
(Linne)) are very closely related. Both groups
have the columellar folds rather steeply
ascending with the most anterior one the
strongest and the posterior varying greatly in
number and sometimes on a more or less
prominent columellar pad. In sculpture and
shape one can find among the European
Eocene species an almost complete gradation
from V. spinosa (Linne, 1767) through

luctator Solander in Brander, 1766 — scalaris
Sowerby, 1843 — ambigua Solander in
Brander, 1766 - suturalis Nyst, 1836 -
crenulifer Bayan, 1870, to digitalina Lamarck,
1811, a species close to the type species of
Volutocorbis. It is therefore difficult to
determine the limits of these groups, and
therefore for the present I consider Voluto-
corbis Dall as the generic name to be used,
with Volutospina Newton as a junior
synonym. As Dai-ragh points out some of the
recent South African species I have described
resemble closely the Miocene species V.
suturalis Nyst, 1836.

Notoplejona Marwick, 1926, seems to be a
genus rather variable in sculpture, judging
from the literature and the two specimens I
have been able to examine in the collection
here. The nature of the columellar folds and
the characters of the sculpture lead me to
place it near Volutocorbis but as a distinct
subgenus because of the strong parietal callus
and broad anterior siphonal notch.

I have been unable to examine a specimen
of Voluta affinis Brocchi, 1814, the type-
species of N eoathleta Bellardi, 1890, but the
figure given by Brocchi shows a species that
seems to belong in Volutospina (i.e. Voluto-
corbis). Cossmann states that affinis is
congeneric with Voluta cithara Lamarck,
1811, the type-species of Volutopupa Dall,
1890, which, judging from the figure of
affinis, seems unlikely. Until the protoconch
of V. affinis can be examined and described, I
am inclined to add Neoathleta to the
synonyms of Volutocorbis Dall, 1890. Unfor-
tunately, the date of publication of Neoath-
leta Bellardi is 6 April 1890, while that of
Volutocorbis Dall is August 1890, so that
Neoathleta would replace Volutocorbis as a
generic name, if my surmise on the allocation
of affinis is correct. However, because of the
present uncertainty as to the nature of the
protoconch of the species, I am continuing to
use Volutocorbis, and consider Neoathleta to
be a genus inquirendus for the present.

DeiII, in 1890, proposed the name Voluto-
pupa as a section of Volutilithes for a group
of species with a high, many-whorled,
relatively large protoconch, citing as type

Vol. 88(2)

THE NAUTILUS

Voliita cithara Lamarck. This name, as stated
above, Cossmann placed in the synonymy of
Neoathleta Bellardi, and included in the group
a number of Paris Basin species, some of
which undoubtedly do not belong here. The
only one that is definitely congeneric with V.
cithara is lyra Lamarck, and V. lineolata
Deshayes also is probably a Volutopupa. I
have examined the protoconch of V. biilbula
Lamarck, 1803, and find that it possesses a
small, conical protoconch with few whorls,
and thus should be placed in Volutocorbis.
Volutopupa can be retained as a subgenus of
Volutocorbis for those species with a
relatively large, elevated-conical, multispiral
protoconch, and a rather thin shell with a
more less inflated last whorl.

The Australian species, that Darragh places
in Athleta (Ternivoluta), and of which I have
been able to examine several lots of
antiscalaris levior (McCoy, 1866) and anticin-
gulata McCoy form indivisa McCoy, 1866, I
would place in the "Volutospina section" of
Volutocorbis.

Ternivoluta Martens, 1897, is definitely
worthy of subgeneric rank under Voluto-
corbis because of its large, paucispiral,
deviated protoconch. The Australian Eocene
to Miocene species that Darragh placed in
Ternivoluta belong in Volutocorbis since they
possess a protoconch typical of this group and
the posterior columellar folds are not placea
on a columellar pad that is generally found in
Ternivoluta.

Volutocorbis nana Rehder, new species
Figs. 1-4

Diagnosis — Shell small, with strong axial
ribs and obscure spiral sculpture, a thick outer
lip, and four to five folds on the columellar
wall. Closest to V. gilchristi (Sowerby, 1902),
which is strongly subsuturally channeled, with
stronger spiral sculpture, and more pro-
nounced columellar folds.

Range — Off southern Zululand, Natal,
South Africa, in 160-180 fathoms.

Description — Shell small, 20.6 to 23.5 mm
(3/4 to 7/8 inches) in length, ovate, rather
stout, color of dead shells dull ivory white.

Protoconch depressed-mammillate, of about
I'/q smooth whorls, early postnuclear whorls
marked by rather sharp axial riblets, 20 in
second postnuclear whorl, marked by two
increasingly prominent nodes, one subsutural
and the other stronger; the narrow platform-
like subsutural ramp and the strong nodes at
the shoulder give the early postnuclear whorls
a stepped appearance; in the penultimate and
ultimate whorls the subsutural ramp becomes
gradually more inclined and the subsutural
row of nodes less angulate. The last whorl
with 16 and 18 axial ribs in the two
specimens seen, showing obscure minor nodes
below the shoulder, marking the presence of
obscure spiral ridges, which continue anter-
iorly to the neck where they become rather
strong cords; in the mid-portion of the last
whorl they are visible only as very faint nodes
on the ribs. Aperture narrow; outer lip gently
arcuate, broad, thickened internally, and
varicose, possibly obscurely denticulate in
fresh specimens; inner lip weakly angled at
juncture of parietal and columellar portions,
the latter with 7 or 8 low rounded folds of
varying strength, the anteriormost one the
largest. Parietal callus thin, obscure.

Material — Holotype: off coast of southern
Zululand, Natal, in 160-180 fathoms,
attached to Xenophora pallidula Reeve,
USNM 709351. Paratype: same locality as
holotype; also attached to Xenophora palli-
dula Reeve; Fuller Collection.

Measurements (mm)—

length width no. whorls

Holotype 23.5 12.5 6V<i

Paratype 20.6 11.0 6

Remarks — This species is distinct because
of its small size (the holotype has the same
number of whorls as the holotype of V.
semirugata Rehder and Weaver, 1974,
measuring 45.1 mm, almost twice as long),
relatively strong axial riblets, without obvious
spiral sculpture on the upper parts of the
whorls, and the thickened, varicose outer lip.

Volutocorbis mozambicana Rehder, 1972

1972. Volutocorbis mozambicana Rehder.
The Veliger, vol. 15, p. 12, figs. 3-5, 7-9.

36 THE NAUTILUS

April 30, 1974

Vol. 88 (2)

I have recently received a specimen of this
species trawled off Durban, which extends the
previously known range of this species
southward for 650 miles.

Through the kindness of Mr. Richard N.
Kilburn I have been able to examine the
holotype of Volutocorbis glabrata Kilburn,
1971. This species is somewhat larger, with a
relatively shorter spire, and a last whorl which
is smooth rather than strongly sculptured as
in mozambicana; the whorls lack the sub-
sutural shelf seen in the latter species.

Volutocorbis kilbumi Rehder, new species
Figs. 5-8

Diagnosis — Shell smooth except for very
faint, obscure, irregular spiral threads, and
with a pronounced and narrowly canaliculate
suture. Outer lip moderately thickened and
recurved, narrowly varicose externally.

Range — From off Ilha Bazaruto, Inham-
bane, Mozambique, to off Durban, Natal,
South Africa in 180 to 280 fathoms.

Description — Shell of medium size, 33 to
39.2 mm (IVa to 1'/: inches) in length, ovately
obconical with evenly convex whorls
separated by a deeply impressed suture. Color
dark grayish yellow (Kelly and Judd, 1965;
color No. 91), the body whorl with distant
reddish brown spots below the suture,
occasionally prolonged into streaks, and with
obscure pale maculations over the whole
whorl, these becoming darker and more or
less arranged in spiral bands towards the
apertural outer lip; the bands mark the varix
of the outer lip with rectangular maculations.
Protoconch conical-mammillate, consisting of

2'/4 smooth convex whorls with impressed
suture. Early postnuclear whorls with flat-
tened subsutural shelf which gradually
becomes convex as the suture deepens and
becomes canaliculate. Postnuclear whorls
rather high and weakly convex, resulting in a
rather narrowly conical spire; whorls smooth,
without sculpture, except for very weak,
obscure spiral ridges and irregular growth
ridges. Aperture narrowly elongate, outer lip
gently arcuate, thickened and reflected,
smooth; inner lip rather straight, only slightly
angled at juncture of parietal and columellar
portions; columellar lip with a thickened
callus on which are situated 9 to 12 folds, the
7 to 10 upper or posterior ones separated
from the two anterior ones by a more
pronounced gap; of the latter two the
posterior one is large, the anterior one low
and broad. Siphonal canal rather broad and
open. Parietal callus very thin.

Material — Holotype: 15 miles off Durban,
Natal, in 280 fathoms; USNM 709352.
Paratype No. 1: 10-15 miles off Durban,
Natal, in 280 fathoms; Boswell Collection.
Paratype No. 2: off Ilha Bazaruto, Inham-
bane, Mozambique, in 180 fathoms; ex A.
Visage; Natal Museum Moll. No. 9769.

Measurements (

mm) —

length

width

no. whorls

Holotype

(USNM 709352)

39.2

18.3

ev*

Paratype #1

(Boswell Colin.)

38.1

18.5

6'/4

Paratype #2

(Natal Museum

Moll. 9769)

33.0

15.1

6'/fe

FIGS. 5-8. Volutocorbis kilbumi Rehder, new
species: FIGS. 5, 7, holotype, USNM 709352,

39.2 mm. in length. FIGS. 6, 8, paratype,
Boswell Colin., 38.1 mm. in length.

Vol. 88(2)

THE NAUTILUS

Remarks — This distinctive species is not
close to any known forms of Volutocorbis.
Paratype No. 2, from off Mozambique, is an
immature specimen with a thin, not fully
formed outer lip.

This species is named for Mr. Richard N.
Kilburn of the Natal Museum,
Pietermaritzburg, Natal, in appreciation of his
important contributions to our knowledge of
the molluscan fauna of this part of the South
African coast.

LITERATURE CITED

Cossmann, M. 1899. Essais de Paleocon-
chologie Comparee. Livr. 3: 201 pp., 8 pis.

Cossmann, M. 1907. [Review of] A Review

of the American Volutidae, by W. H. Dall.

Revue Crit. Paleozoologie 11: 191.
Cossmann, M. 1909. Essais de Paleocon-

chologie Comparee. Livr. 8: 248 pp., 4 pis.
Darragh, T. A. 1971. Revision of the

Australian Tertiary Volutidae (Mollusca;

Gastropoda). 1. The subfamily Athletinae.

Jour. Malac. Soc. Australia 2 (2): 163-185,

pis. 14-16, text figs. A-C.
Fischer, W. L., P. U. Rodda, and J. W.

Dietrich. 1964. Evolution of Athleta

petrosa stock (Eocene, Gastropoda) of

Texas. Bur. Econ. Geol., Univ. Texas Publ.

No. 6413: VI+ 117 pp., 11 pis., 33

text-figs.

BOOK REVIEW

INTERTIDAL MOLLUSKS OF IQUIQUE,
CHILE. By Marincovich, Louie. Los
Angeles County Natural History Museum,
Science Bull. 16, 49 pp., 102 figs. Feb. 20,
1973. Available from Los Angeles County
Museum Bookshop, $2.35 (postpaid, in-
cluding tax).

Although the west coast of South America
was early explored and the first mollusks
from there were described as long ago as
1782, the fauna has remained rather sketchily
represented in most collections. Literature is
scanty and scattered. The present work results
from two collecting trips, comprising a total
of six months of intertidal collecting. Some
87 molluscan species and one brachiopod are

discussed, all being well illustrated by
photographs and by line drawings of radulae
(except for five forms that are specifically
unidentified). One new genus, Salitra, is
proposed in the family Columbellidae. The
type species, S. radwini, also is new. Ten
other new species are described, in the genera
Nucula, Lyonsia, Tricolia, Eatoniella,
Eatonina, Fartulum, Aesopus, and Iselica.

The systematic account is well docu-
mented, and the utility of the paper is
increased by discussion of biogeography and
by a review of pertinent literature. The author
is to be commended for this useful work.

Myra Keen, Department of Geology,
Stanford University, California

38 THE NAUTILUS

April 30, 1974

Vol. 88(2)

THE DISTRIBUTION and ECOLOGY of
COMMON MARINE and ESTUARINE PELECYPODS
in the DELAWARE BAY AREA'
Don Maurer' , Les Watling' , Glenn Aprill^

Field Station' ^ Dept. Environmental Sciences

College of Marine Studies University of Virginia

University of Delaware Charlottesville, Va., 22903

Lewes, Delaware

ABSTRACT

Samplings from 1967 to 1973 of the marine-estuarine pelecypods of the
Delaware Bay region indicates that about half of the 44 common species are
true estuarine while the other half are evenly distributed between euryhaline
and stenohaline marines, with only a single oligohaline species, Rangia
cuneata. The latter case is a northern range extension for this southern
species.

INTRODUCTION

This research was undertaken to determine
the distribution and ecology of common
marine and estuarine pelecypods in the
Delaware Bay area. Increased attention to
pollution problems has renewed interest in
benthic ecology. As a result, a series of local
surveys have been conducted dealing with
different taxonomic groups (Watling and
Maurer 1972 a, b, Watling et al, 1973). This
paper represents a part of those surveys.

Lowden (1965) provided an annotated
checklist of marine molluscs which covered
Delaware Bay and New Jersey ocean beaches
and enclosed bays. Watling and Maurer (1974)
prepared a guidebook for the Delaware Bay
region fauna which included a taxonomic key
for the marine and estuarine molluscs.
Moreover, some studies on pelecypods col-
lected among oyster beds were also reported
(Maurer and Watling 1973 a, b).

METHODS

This report is based on samples collected
from 1967 to 1973 with a wide variety of
sampling gear; epibenthic dredge, oyster
dredge, hard clam dredge, hydraulic surf clam
dredge. Van Veen bottom grab (0.1 m' ),
Petersen bottom grabs (0.1 m^ 1/15 m" ).
Several areas on Coast and Geodetic Survey

^Contribution No. 84, College of Marine Studies.

Maps 1218 and 411 which received intensive
sampling are: 1) quantitative samples off Cape
Henlopen, 13 transects from the capes to
Woodland Beach, Cape Henlopen flat, Reho-
both, Indian River, and Little Assawoman
Bays, eight miles east of Rehoboth, 2)
qualitative samples include the above si.es
together with heavy sampling in Delaware's
oyster beds. All quantitative samples were
sieved through a 1.0 mm mesh screen and the
residual on the screen was preserved in 10%
buffered formalin. Selected organisms from
the qualitative (dredge) samples were pre-
served in a similar manner.

Standard hydrographic data (temperature,
salinity, dissolved oxygen) were collected for
many of the samples together with samples of
the sediment. The sediment samples were
dried and sieved through a graded sieve series
to determine sediment particle size.

RESULTS AND DISCUSSION

A list of the species discussed in this paper
together with a summeiry of their ecology is
presented in telescopic form. Salinity values,
spawning and substrate data are derived from
our data in the Delaware Bay region and from
other sources (Chanley 1958, Loosanoff ef al.
1966, Chanley and Andrews 1971). Notations
for burrowing behavior are drawn from
Stanley (1970). Carriker (1967) developed a
scheme of geographic divisions, salinity

Vol. 88(2)

THE NAUTILUS

ranges, types and distribution of organisms in
estuaries. His scheme is adopted to facilitate
comparison with other estuaries.

Among 44 species, 20 species are desig-
nated as true estuarine, 11 as euryhaline
marine, 12 as stenohaline marine, and one as
oligohaline. These designations represent the
maximum distribution of these species rather
than exceptional or marginal occurrences.

OLIGOHALINE

Rangia cuneata is the only local oligohaline
species. It was reported from upper Chesa-
peake Bay and Elk River, Maryland (Pfitzen-
meyer and Drobeck 1964). Subsequently,
Gallagher and Wells (1969) indicated that it
should be expected in upper Delaware Bay.
Dead shells were collected near the eastern
end of the Chesapeake-Delaware Canal by the
Field Station. Recently several specimens
were sampled from Delaware waters (J.
Lindsay and Ron Smith, personal communi-
cation). This represents a northern range
extension for this species. One specimen (29
mm in length) was collected August 20, 1971
in 1.0 m of water from sand bottom off
Oakwood Beach, New Jersey. A second
specimen was collected August 15, 1972 in
1.8 m of water from a mud and detritus
bottom 200 m north of Appoquinimink
Creek. Although not normally considered as
oligohaline species, Mya arenaria and Macoma
balthica have been reported from salinities as
low as 5 %o in European and American
estuaries (Segerstrale 1957, Bird 1970). These
species must occur in the bay in great
abundance between the St. Jones River and
Woodland Beach because the volume of their
shell debris is large. Other local species
(Modiolus demissus and Brachiodontes recur-
vus) also extend their range into areas where
salinity becomes lower than 5 -L , but they
more properly belong to true estuarine
species.

TRUE ESTUARINE

Amygdalum papyria, Mysella planulata,
and Modiolus demissus are found attached by
byssal threads to oysters. In the rivers, M.
demissus and A. papyria are most commonly
attached to marsh vegetation or partly buried

in soft sediment. The ribbed mussel, M.
demissus, is more common intertidally on
roots of Spartina alterniflora than subtidally
(Lent 1967), while A. papyria is always far
less abundant than M. demissus and occurs
subtidally. The ribbed mussel is uncommon in
the bay except at Woodland Beach. Here the
proximity of the marshes as a source of brood
stock favors heavy setting on any firm
substrate. Kunkel (personal communication)
informs us that the hooked mussel, Brach-
iodontes recuruus was at one time frequently
collected above the Cohansey River, but is
now very rare. The reason for its decline is
unknown, but it was coincident with the
mid-1960's drought.

Two bivalves show an affinity for a specific
substrate. Petricola pholadiformis and Barnea
truncata are characteristic of sections of the
Murderkill, St. Jones, and Leipsic rivers with
substrates of hard clay and packed marsh
debris.

Infaunal species such as Macoma balthica,
M. tenia, Mya arenaria, Ensis directus, Solen
viridis, Tagelus plebeius, and T. divisus mainly
occur in mud, fine sand, and shelly-mud
bottoms. High density (200/0.1 m' ) popula-
tions of juvenile razor clams, Ensis directus,
were found in sandy shoal areas bordering the
ship channel, particularly from the mouth of
the bay to the Miah Maul shoal. The above
species together with Solemya velum (50
individuals per 1/15 m^ ) is also very abundant
in the fine sands of Rehoboth and Indian
River Bays. The soft clam, Mya arenaria,
occurs in mud (> 50% silt-clay) bottoms of
the smaller bays.

The oyster, Crassostrea virginica, is a
dominant member of the estuarine com-
munity and locally ranges from the Cape May
Flat to north of Arnolds Point. Maximum
development of natural seed beds extends
from Woodland Beach to Port Mahon on the
Delaware side of the Bay and from Egg Island
Point to north of Arnolds Point on the New
Jersey side. In addition to its commercial
significance, the oyster forms the nucleus of a
community that contains many species
(Maurer and Watling 1973 a, b).

Anomia simplex was formerly reported in

40 THE NAUTILUS

April 30, 1974

Vol. 88(2)

abundance in New Jersey oyster beds where
the salinity is above 20 %» (Kunkel, personal
communication). Our experience with A.
simplex is primarily restricted to Rehoboth
and Indian River Bays where it is found
attached to algae, rocks, and shells.

Two small (< 2 cm) bivalves. Gemma
gemma and Mulinia lateralis, are locally very
common, but their maximum distributions
are dissimilar. Mulinia lateralis is found in
muddy and sandy substrates and is one of the
most abundant pelecypods in Delaware Bay.
Great numbers (8-10,000/0. Im^ ) of M.
lateralis shells in channels and troughs near
the mouth of the bay attest to its abundance.
Gemma gemma inhabit a silty (20% silt-clay)
or muddy-sand substrate and occur in the bay
in relatively small numbers. It is, however,
extremely abundant in Rehoboth and Indian
River Bays, where counts of subtidal popula-
tions were as high as 280,000/m' . Both
species are ecologically significant, because a
number of fish, invertebrates, and birds feed
on these bivalves (Sellmer 1967, Calabrese
1969).

The hard clam, Mercenaria mercenaria, is
commonly collected in fine sand with some
clay. In Delaware Bay it ranges from
Woodland Beach to the ocean, although it is
most abundant in the lower Bay from south
of Port Mahon to Broadkill Beach (Keck et al.
1972). Further, the hard clam occurs in
commercial numbers in Rehoboth and Indian
River Bays. Coincident with the occurrence of
the hard clam in the smaller bays is that of
Pilar morrhuana, which is commonly col-
lected but in considerably lower numbers.
Both species are on the borderline between
true estuarine species and euryhaline marine
species because they frequently occur near
high salinity inlets or in the ocean.

EURYHALINE MARINE

Two species which occur in oceanic salinity
but also extend into the estuary are the wood
borers, Bankia gouldi and Teredo navalis.
Evidence of their work can be found in
wooden pilings along Delmarva and Delaware
Bay beaches. Teredo navalis has a wide
tolerance to salinity and B. gouldi occurs in

Chesapeake Bay in water with a mean salinity
of 9.3 %o and a range of 3.3 °oo— 15.6
%„ (Scheltema and Truitt 1954, Nair and
Saraswathy 1971 ). Among other euryhaline
marine species Siliqua costata and Tellina
agilis are considered rapid burrowers and
Corbula contracta, Lyonsia hyalina, Anadara
ovalis, A. transversa, and Noetia ponderosa
are considered slow burrowers (Stanley
1970). Tellina agilis is a dominant species in
fine sand (0.25 mm median sediment size)
near the mouth of the Bay. A codominant
species occurring with T. agilis is Nucula
proximo which is common in sediments with
high (> 50%) silt-clay content (Maurer et al.
1973). Tellina agilis is also common on the
Cape Henlopen flats. This tellinid may also
occur with L. hyalina, which is most common
in sediment with 20-40% silt-clay. The ark
shells, Anadara transversa and .4. ovalis, occur
in the ocean but are more frequently
collected in algae beds of the smaller bays. In
contrast, Noetia ponderosa is more common
in the ocean.

STENOHALINE MARINE

Tellina versicolor, Donax fossor, and
Spisula solidissima occur very near open shore
beaches. In fact, Donax fossor may be
considered an intertidal species. These species
are primarily restricted to clean sand with
shell and gravel. The surf clam, Spisula
solidissima, is an important offshore com-
mercial species (Yancey and Welch 1968).
Laboratory observations showed that S.
solidissima was unable to survive the diurnal
tidal fluctuation in the Broadkill River
(14-28 %o ).

Species such as Pandora gouldiana, Astarte
undata, Venericardia borealis, Cerastoderma
pinnulatum, Abra aequalis, and Arctica
islandica occur in deeper water (> 12 m) in
coarse sand. However, P. gouldiana is
collected from the Cape Henlopen flat.
Fragments of Cyrtopleura costata shells com-
monly wash ashore on Delaware's Atlantic
coast but we have not collected any alive.
None of these species is abundant with the
exception of A. islandica. It probably occurs
in commercial numbers, but has not been
vigorously marketed.

Vol. 88(2)

THE NAUTILUS

Yoldia Umatilla also is common in the
ocean, but it has the same affinity for
sediment with high silt-clay content as N.
proxima. Both species occur together locally.
Nucida proxima is more dominant in shallow
and semi-enclosed water than Yoldia Umatilla.
Mytilus edulis is found attached to rocks,
wrecks, and jetties near the mouths of bays
and in the ocean. It occasionally occurs in
such numbers to form small lenticular reefs in
rivers (e.g. Broadkill) along the lower Bay.

The Bay scallop, Argopecten irradians is
occasionally obtained in Rehoboth and Indian
River Bay. This species is not abundant, but
when it occurs it is associated with algae in
the smaller bays. We have found it only
occasionally in the ocean, but it may be more
common there.

COMMUNITY STUDIES

In an earlier study, the habitat zone,
substrate, form, and feeding type of mollus-
can communities of Beaufort, North Carolina,
were described (Bird 1970). With the caveats
of different sampling design, methods, and
treatment of pelecypod molluscs alone,
comparison of Bird's data with ours show the
following similarities and differences. From
estuary mouth to the head he named three
communities: Tellina, Mulinia — Syndosmya
[Abra] , Retiisa; Syndosmya [Abra] — Ali-
gena; and Macoma balthica. Only the Macoma
community was sharply delineated. The
association of the estuary mouth graded into
the shallow open-ocean community of the
area, the Tellina — Spisula community.

There was no attempt here to define
pelecypod communities per se. Instead,
particular suites of species were recognized
based on salinity distribution. Following
Carriker's (1967) outline for biota and
salinity divisions, pelecypods (Spisula, Donax,
Astarte, Venericardia) occurring in local
stenohaline marine conditions would proba-
bly agree with Bird's (1970) open ocean
community (Spisula — Tellina). Pelecypods
(Tellina, Lyonsia, Anadara, Corbula) locally
recognized as euryhaline marine species may
be equated with Bird's Tellina, Mulinia —
Syndosmya [Abra] Retusa community.

Those species (Macoma, Modiolus, Mulinia,
Brachiodontes ) which are true estuarine forms
may fit Bird's Macoma community.

Two other comparisons can be made. The
range of salinity of species distribution
reported by Bird (1970) is narrower than
salinity ranges for similar species in this study.
This tends to telescope molluscan assemblages
towards the mouth of the estuary. As a result,
differences between his results and ours are
more superficial than significant. The impor-
tant fact remains that the relative sequence of
pelecypod assemblages is very similar in both
areas. He commented that community bound-
aries were gradational even between open
ocean and estuary-mouth communities.
Gradual shifting of relative abundance of the
most abundant species rather than wholesale
change in species composition characterized
community flux. We agree with Bird's (1970)
findings in that in some cases it was difficult
to distinguish among true estuarine, eury-
haline marine, and stenohaline marine species.
Controlling mechanisms to explain these
differences remain to be studied.

In summary, there are approximately 44
common species of marine-estuarine pelecy-
pods in the Delaware Bay region. As might be
expected about 50% are true estuarine
species. The other 50% are evenly distributed
between euryhaline and stenohaline marine
species with a single bonafide oligohaline
species (Rangia cuneata). The latter is a
northern range extension. The designation of
stenohaline marine and oligohaline species is
easier to determine than euryhaline marine or
true estuarine forms.

SUMMARY OF ECOLOG\

Salinities in parentheses represent values
from published literature, while those not in
parentheses represent our data. The substrate
is classified by median sediment size, in mm:
fine sand, 0.063-0.25; medium sand,
0.25-0.50; coarse sand, 0.50-2.00.

Rangia cuneata (Gray): Salinity, 0-10 %^ ,
(0-20 °oo ), oligohahne; spawning months,
April through June; substrate, silt-clay and
fine sand; mode, infaunal suspension feeder,
slow burrower.

42 THE NAUTILUS

April 30, 1974

Vol. 88(2)

Brachiodontes recurvus (Rafincsque):
Salinity, 8-15 °o'. , (0-20 °o. ), true estuarine;
spawning months, April through December;
substrate, rocks and oysters; mode, epifaunal
suspension feeder with strong hyssus.

Modiolus demissus (Dillwyn): Salinity,
5-25 %o, (2-30 °oo ), true estuarine; spawning
months. May through October; substrate,
marsh grass and algae, occasionally rocks;
mode, semi-buried suspension feeder, weak
byssus.

Barnea truncate (Say): Salinity, 13-25 %» ,
(10-30 ?oo ), true estuarine; spawning months,
April through November; substrate, hard clay;
mode, infaunal suspension feeder, moderately
rapid burrower.

Cyrtopleura costata (Linne): Salinity,
13-25 %o , (10-30 %o ), true estuarine; sub-
strate, hard clay; mode, infaunal suspension
feeder, moderately rapid burrower [not found
living] .

Amygdalum papyria Conrad: Salinity,
8-25 °oo , (5-25 °oo ), true estuarine; substrate,
marsh grass, algae and oysters; mode,
epifaunal suspension feeder with byssus.

Mya arenaria (Linne): Salinity, 5-20 %<, ,
(5-25 %o ), true estuarine; spawning months,
March through May and September through
December; substrate, silt-clay through
medium sand; mode, infaunal suspension
feeder, slow burrower.

Macoma balthica (Linne): Salinity,
10-25 %o , (5-25 %o ), true estuarine; spawning
months, March through May and August
through November; substrate, silt-clay
through medium sand; mode, infaunal deposit
feeder, moderately rapid burrower.

Bankia gouldi Bartsch: Salinity, 15-35 %= ,
(10-35 %o ), euryhaline marine; substrate,
wood; infaunal suspension feeder, slow
burrower.

Teredo navalis Linne: Salinity, 15-35 %» ,
(10-35 °oo ), euryhaline marine; spawning
months, June through October; substrate,
wood; mode, infaunal suspension feeder, slow
burrower.

Macoma tenia (Say): Salinity, 15-25 %o ,
(10-30 %o ), true estuarine; substrate, silt-clay
through medium sand; mode, infaunal deposit
feeder, moderately rapid burrower.

Solen viridis Say: Salinity, 13-28 °=o ,
(7-28 V ), true estuarine; substrate, fine sand
and medium sand; mode, infaunal suspension
feeder, rapid burrower.

Ensw directus Conrad: Salinity, 13-28 °.'o ,
(7-32 °.. ), true estuarine; spawning months,
January through April; substrate, fine sand
and medium sand; mode, infaunal suspension
feeder, rapid burrower.

Siliqua costata (Say): Salinity, 15-25 V
(15-28 °oo ), euryhaline marine; substrate
silt-clay through medium sand; mode
infaunal suspension feeder, rapid burrower.

Tagelus plebeius (Lightfoot): Salinity
13-30 °oo , (13-28 "oo ), true estuarine: sub
strate, silt-clay through medium sand; mode
infaunal deposit feeder, slow burrower.

Mulinia lateralis (Say): Salinity, 13-28 /.<.
(10-35 ' ), true estuarine: spawning months
March through November; substrate, silt-clay
through medium sand; mode, infaunal suspen-
sion feeder, moderately rapid burrower.

Corbula contractu Say: Salinity, 20-30 °U ,
(15-35 °»c ), euryhaline marine; substrate,
silt-clay and fine sand; mode, infaunal
suspension feeder, slow burrower.

Crassostrea virginica (Gmelin): Salinity,
13-30 °oo , (0-35 °ic ), true estuarine; spawning
months, June through September; substrate,
rocks and shells; mode, epifaunal suspension
feeder, in clusters.

Solemya velum Say: Salinity, 17-25 ?C, ,
(15-28 °^o ), true estuarine; substrate, silt-clay
and fine sand; mode, infaunal suspension
feeder, rapid burrower.

My sella planulata Stimpson: Salinity,
15-25 °L , (13-28 ".o ), true estuarine; sub-
strate, algae, hard shell, rocks; mode,
epifaunal suspension feeder, weak byssus.

Anomia simplex Orbigny: Salinity,
15-30 °oo , (10-30 °oo ), true estuarine;
spawning months, April through October;
substrate, algae, hard shells, rocks; mode,
epifaunal suspension feeder, calcified byssus.

Pitar morrhuana (Linsley): Salinity,
17-30 %o, (15-35 °oo ), true estuarine;
spawning months. May through August;
substrate, silt-clay through medium sand;
mode, infaunal suspension feeder, moderately
rapid burrower (?)

Vol. 88(2)

THE NAUTILUS

Mercenaria mercenaria (Linne): Salinity,
15-30 °oo (10-35 %o ), true estuarine; spawn-
ing months, May through October; substrate,
silt-clay through medium sand, some shell;
mode, infaunal suspension feeder, moderately
rapid burrower.

Tagelus divisus (Spengler): Salinity,
15-25/00, (15-29 %o ), true estuarine; sub-
strate, silt-clay through medium sand; mode,
infaunal deposit feeder, rapid burrower.

Lyonsia hyalina (Conrad); Salinity,
18-30 %o , (15-28 °^ ), euryhaline marine;
spawning months, February through May;
substrate, silt-clay and fine sand; mode,
infaunal suspension feeder, slow burrower.

Tellina agilis Stimpson: Salinity, 13-35 %o ,
(12-35 %c ), euryhaline marine; spawning
months, March through July; substrate,
silt-clay through medium sand; mode,
infaunal deposit and suspension feeder, rapid
burrower.

Tellina versicolor DeKay: Salinity,
20-35 %o , (15-35 %o ), stenohaline marine;
substrate, fine sand through coarse sand;
mode, infaunal deposit and suspension feeder,
rapid burrower.

Anadara ovalis (Bruguiere): Salinity,
15-30 %o, (15-35 %o ), euryhaline marine;
spawning months. May through October;
substrate, fine sand through coarse sand;
mode, infaunal suspension feeder, weak
byssus, slow burrower.

Argopecten irradians (Lamarck): Salinity,
20-35 %o , (17-35 %o ), stenohaline marine;
spawning months, April through August;
substrate, algae; mode, vagile suspension
feeder, weak byssus.

Gemma gemma (Totten): Salinity,
18-30 %o , (13-32 fo'o ), true estuarine; sub-
strate, silt-clay and fine sand; mode, infaunal
suspension feeder, moderately rapid bur-
rower.

Anadara transversa (Say): Salinity,
18-30 %o, (15-32 "o'o ), euryhaline marine;
spawning months. May through September;
substrate, algae, silt-clay through medium
sand; mode, infaunal suspension feeder, weak
byssus, slower burrower.

Noetia ponderosa (Say): Salinity, 17-30 %» ,
(15-35 %o ), euryhaline marine; spawning

months, June through November; substrate,
algae, silt-clay through medium sand; mode,
infaunal suspension feeder, weak byssus, slow
burrower.

Mytilus edulis Linne: Salinity, 20-35 %» ,
(15-35 %o), stenohaline marine; spawning
months, January through December; sub-
strate, rock, shell; mode, epifaunal suspension
feeder, strong byssus in clusters.

Petricola pholadiformis Lamarck: Salinity,
15-29 %o , (10-32 %o ), euryhaline marine;
spawning months, March through November,
substrate, hard clay; mode, infaunal suspen-
sion feeder, moderately rapid burrower.

Pandora gouldiana Dall: Salinity, 23-35 %„ ,
(20-35 %o ), stenohaline marine; substrate, fine
sand through coarse sand; mode, infaunal
suspension feeder, slow burrower.

Astarte undata Gould; Salinity, 25-35 %» ,
(22-35 %o ), stenohaline marine; substrate,
medium sand and coarse sand, shell; mode,
infaunal suspension feeder, slow burrower.

Nucula proxima Say: Salinity, 25-35 %» ,
(20-35 %o ), euryhaline marine; substrate,
silt-clay and fine sand, organic mud; mode,
infaunal deposit feeder, moderately rapid
burrower.

Venericardia borealis (Conrad): Salinity,
25-35 %o , (22-35 %» ), stenohaline marine;
substrate, medium sand and coarse sand, shell;
mode, infaunal suspension feeder, slow
burrower.

Cerastoderma pinnulatum (Conrad): Salin-
ity, 25-35 %o , (22-35 %» ), stenohaline marine;
substrate, medium sand and coarse sand, shell;
mode, infaunal suspension feeder, moderately
rapid burrower.

Donax fossor Say: Salinity, 29-35 %o ,
(25-35 %o), stenohaline marine; spawning
months, June through October; substrate,
medium sand and coarse sand, shell; mode,
infaunal suspension feeder, rapid burrower.

Abra aequalis (Say): Salinity, 29-35 %» ,
(25-35 %o ), stenohaline marine; substrate,
medium sand and coarse sand, shell; mode,
infaunal deposit feeder (?), moderately rapid
burrower (?)

Yolida limatula (Say): Salinity, 25-35 %o ,
(22-35 %„ ), stenohaline marine; substrate,
silt-clay and fine sand, organic mud; mode.

44 THE NAUTILUS

April 30, 1974

Vol. 88 (2)

infaunal deposit feeder, rapid burrower.

Spisula solidissima (Dillwyn): Salinity,
27-35 %o , (10-35 %o ), stenohaline marine;
spawning months, March through May and
September through November; substrate,
clean, coarse sand, shell, medium sand; mode,
infaunal suspension feeder, rapid burrower.

Arctica islandica (Linne): Salinity,
30-35 %o , (28-35 %. ), stenohaline marine;
spawning months, June through October;
substrate, clean, medium sand and coarse
sand, shell; mode, infauna.

ACKNOWLEDGMENTS

Our associates, Wayne Leathem and Peter
Kinner, provided much of the raw data for
this paper. Because of their efforts we were
able to expand the species list. Mr. John
Lindsay and Mr. Ron Smith, Ichthyological
Associates, generously shared their collecting
data on Rangia cuneata. Since the latter is a
northern range extension, Mr. Lindsay and
Mr. Smith deserve recognition for their
contribution. Finally, Dr. R. Tucker Abbott
kindly checked several identifications and
encouraged us to develop this account.

LITERATURE CITED

Bird, S. O. 1970. Shallow marine and
estuarine benthic moUuscan communities
from area of Beaufort, North Carolina,
Amer. Assoc. Pet. Geol, Bull. 54 (9):
1651-1676.

Calabrese, A. 1969. Reproductive cycle of the
coot clam, Mulinia lateralis (Say), in Long
Island Sound. Veliger 12 (3): 265-269.

Carriker, M. R. 1967. Ecology of estuarine
benthic invertebrates: a perspective. In:
Estuaries (ed. Lauff, G. H.) Amer. Assoc.
Adv. Sci. Publ. 83: 442-487.

Chanley, P. E. 1958. Survival of some juvenile
bivalves in water of low salinity. Proc. Nat.
Shell. Assoc. 48: 52-65.

Chanley, P. E. and J. D. Andrews. 1971. Aids
for identification of bivalve larvae of
Virginia. Malacologia 11 (1): 45-119.

Gallagher, J. S. and H. W. Wells. 1969.
Northern range extension and winter
mortality of Rangia cuneata. Nautilus 83
(1): 22-25.

Lent, C. 1967. Effect of habitat on growth
indices in the ribbed mussel, Modiolus
(Arcuatula) demissus. Chesapeake Sci. 8
(4): 221-227.

Loosanoff, V. L., H. C. Davis and P. E.
Chanley. 1966. Dimensions and shapes of
larvae of some marine bivalve mollusks.
Malacologia 4 (2): 351-435.

Lowden, R. D. 1965. The marine Mollusca of
New Jersey and Delaware Bay, an anno-
tated checklist. Proc. Phila. Shell Club. 1
(8-9): 5-61.

Maurer, D. and L. Watling. 1973 a. Studies on
the oyster community in Delaware: The
effects of the estuarine environment on the
associated fauna. Inter, ges. Revue der
Hydrobiologie 58 (2): 161-201.

Maurer, D. and L. Watling. 1973 b. The
biology of the oyster community and its
associated fauna in Delaware Bay. Delaware
Bay Report Series, Volume 6 (D. F. Polls,
ed.). College of Marine Studies, University
of Delaware, pp. 1-97.

Nair, N. B. and M. Saraswathy. 1971. The
biology of woodboring teredinid molluscs,
p. 336-509. In: Advances in Marine
Biology, Vol. 9 (ed. F. S. Russel and M.
Younge), Academic Press.

Pfitzenmeyer, H. T. and K. G. Drobeck. 1964.
The occurrence of the brackish water clam,
Rangia cuneata, in the Potomac River,
Maryland. Chesapeake Sci. 5 (4): 209-212.

Scheltema, R. S. and R. V. Truitt. 1956. The
shipworm Teredo navalis in Marylemd
coastal waters. Ecol. 37 (4): 841-843.

Segerstrale, S. G. 1957. Baltic Sea. In:
Treatise on Marine Ecology and Paleo-
ecology Vol. 1 (ed. J. W. Hedgpeth) Geol.
Soc. Amer. Mem. 67, 751-802.

Sellmer, G. P. 1967. Functional morphology
and ecological life history of the gem clam,
Gemma gemma, (Eulamellibranchia: Vener-
idae). Malacologia 5 (2): 137-223.

Stanley, S. M. 1970. Relations of shell form
to life habits of the Bivalvia (Mollusca).
Geol. Soc. Amer. Mem. 125: 1-296.

Watling, L. and D. Maurer. 1972 a. Marine
shallow water amphipods of the Delaware
Bay area, U.S.A. Crustaceana. Studies on
Peracarida, Supplement 3: 251-266.

Vol. 88(2)

THE NAUTILUS

Watling, L. and D. Maurer. 1972 b. Shallow
water hydroids of the Delaware Bay region.
Jour. Nat. Hist. 6: 643-649.

Watling, L. and D. Maurer. 1973. Guide to the
macroscopic estuarine and marine inverte-
brates of the Delaware Bay region.
Delaware Bay Report Series, Volume 5 (D.
F. Polls, ed.) College of Marine Studies,
University of Delaware, pp. 1-178.

Watling, L., J. Lindsay, R. Smith and D.
Maurer. 1974. The Distribution of Iso-
poda in the Delaware Bay Region. Int.
Revue ges. Hydrobiol. (in press).

Yancey, R. M. and W. R. Welch. 1968. The
Atlantic Coast surf clam with a partial
bibliography. U. S. Fish & Wild. Serv. Cir.
288: 1-14.

BOOK REVIEW

THE FRESHWATER MOLLUSCS OF THE
CANADIAN INTERIOR BASIN. By
Clarke, Arthur H. 1973. Malacologia,
13(1-2): 1-509, 9 text figures, 9 tables, 87
maps, 28 plates (1-14 in color, 15-28 in
black and white), 35 charts.

Of monographic proportions, this regional
study provides an immense amount of data on
the biology of 103 species and subspecies in
37 genera and subgenera of an area
encompassing more than 1/3 of North
America. Ten families (2 bivalve, 3 proso-
branch and 5 pulmontate) are reviewed with
the sphaeriids, lymnaeids and planorbids
being among the more speciose. For certain
taxonomic groups this study constitutes the
first modern systematic treatment, and many
of the taxa have never been critically
reviewed, properly described or adequately
illustrated.

Geographically, the Canadian Interior Basin
comprises both the Hudson Bay Basin and
the Canadian portion of the Arctic Basin,
including such extensive river systems as the
Mackenzie, Churchill, and Saskatchewan. The
front endpapers provide a colored map of the
principal drainage basins and the rear covers

detail, in color, phytogeographic and geo-
morphic features. Dominating the geologic
scene is the Precambrian Shield, a poor source
of limestone and therefore not particularly
hospitable for shelled animals. A more
suitable substrate, the Hudson Bay Lowland
provides a more calcium rich environment and
is characterized by low species diversity and
by large population sizes typical of highly
variable environments.

Approximately 10 years of field work
during which nearly 600 stations were
sampled and over 3000 lots collected, form a

basis for this study Including material from
various sources, ultimately over 100,000
specimens were examined. In conjunction
with fossil evidence, temperature preferences,
and distributional data, the probable faunal
origins are analyzed for each species. In an
enlightening introduction, previous research
and the geologic history of the area are
surveyed.

The major portion of the text consists of
the systematic section. Although each species
is provided vdth a synonymy, the treatment is
irregular and incomplete. As the author
himself points out, not all synonyms are listed

46 THE NAUTILUS

April 30, 1974

Vol. 88(2)

and few citations of type specimens are
included. For example, rather than attempt to
assess the validity of all North American
nominal Gyraulus, an effort is made to
evaluate the status of all taxa recorded from
the study area. Following a short diagnosis, a
longer, more detailed description is given for
each species. An illustration, a list of
specimens examined and a map of the species'
distribution in the study area are augmented
with comments on overall distribution, a
discussion of biology and ecology, and
remarks on closely related species and
probable synonyms. Clear, dichotomous keys,
with references to page numbers and illus-
trations, aid in identification of each family,
genus, species, and subspecies.

The taxonomy of freshwater mollusks has
always constituted a considerable problem.
Dr. Clarke employed some biometric methods
to describe the variation in these species. He
utilized these data to detect subspecies, to
discover the meaning or implication of
geographically correlated morphometric char-
acteristics, and to describe more fully the
variability exhibited by some species. Adduc-
ing that evidence of gene exchange between
otherwise distinguishable groups of popula-
tions is indicative of the existence of
subspecies whereas no gene exchange means
that two or more distinct species are involved.
Dr. Clarke recognized a dozen polytypic
species, some with as many as 3 subspecies in
the study area. An examination of the
distribution of one of these polytypic species,
for example Valvata sincera with its 3
polytopic subspecies, V.s. sincera, V.s. ontari-
ensis, and V.s. helicoidea shows that all three
may live in the same river system (Albany and
Severn drainages) and even near or in the
same body of water (Lake Nipigon). To me,
such a pattern casts doubt on the interpreta-
tion of these populations as subspecies since
subspecies are, by definition, geographical
isolates.

Certain complex nomenclatorial problems
are resolved. To insure stability and allow the
continued widespread usage of such im-
portant hydrobiid generic names as Amnicola
and Pomatiopsis, a neotype is designated for

Paludina lustrica Say, 1821, the type species
of Amnicola. An attendant oddity is that this
specific name, though having priority, is
considered a nomen oblitum and A. walkeri
Pilsbry, 1898, a subjective synonym, utilized.

Among the outstanding contributions in
this volume are the extremely useful distinc-
tions between easily confused species, the
thorough accounts of previously very poorly
known species, and the comprehensive
analyses of certain species. Lymnaea colum-
ella and Succinea ovalis are very similar and
frequently misidentified, but here they are
clearly differentiated conchologically and
anatomically (p. 293).

Many intrinsically intriguing biological
facts are brought to light. Documenting the
tenacity and perseverance of some mollusks
are the extreme northern occurrences of
certain species: the cosmopolitan sphaeriid
Pisidium casertanum on Baffin and Victoria
Islands, the panboreal physid Aplexa hypno-
rum also on Victoria Island, £ind the Beringian
Lymnaea atkaensis at home on the Arctic
Coastal Plain. Additional specific results
include the synonymization of Lymnaea
emarginata with L. catascopium (p. 328) and
the recognition of the European Gyraulus
albus as distinct from the Nearactic G.
deflectus (p. 396).

In summary, this work is truly a magnum
opus, constituting the most comprehensive
treatment of the mollusks of a faunal area in
North America and the most thorough
analysis of many intriguing taxa. Setting a
high standard of excellence, it forms the
foundation for any future work on the
freshwater mollusks of Canada and, indeed,
the United States. An invaluable treatise and
exemplary source book for the limnologist
and aquatic biologist, it is a must for the
library of any malacologist and a fitting
memorial to the author's late wife, Louise, to
whom the work is dedicated.

Kenneth J. Boss

Museum of Comparative Zoology

Harvard University

Cambridge, Mass. 02138

Vol. 88 (2)

THE NAUTILUS

FROG MOTIFS ON ARCHAEOLOGICAL MOLLUSKS OF

HOHOKAM AND MOGOLLON INDIAN CULTURES

Glenn A. Long

The Baltimore Museum of Art

Baltimore, Maryland 21218

ABSTRACT

Thirty-seven pendants and eight bracelets carved with frog motifs, or
overlaid with turquoise mosaic, comprise this initial checklist. Of the carved
pendants without overlay, several motific groups can be identified. Pendants
and bracelets were made from whole valves of various species, such as
Glycymeris gigantea (Reeve) and G. maculatus (Broderip). Other shells were
used but less frequently. Carved frog pendants are found throughout the
Hohokam and Mogollon culture areas and were frequently excavated in
connection with burials.

This is a preliminary report on carved shell
ornaments from archaeological remains of
prehistoric Indian cultures in the Southwest.
In the current phase of study, a checklist of
frog images is being compiled and motific
groups are being catalogued. For reasons
which go beyond this assembly and subdivi-
sion of objects and data, records are being

made of archaeological contexts in which frog
images were found in the hope that significant
frequency patterns will emerge from the data.
We assume that discovery of carved shell
ornaments in archaeological remains means
that these objects had intrinsic value to
certain prehistoric people. We also assume
that by studying these objects we might

FIG. 1 Overlaid Shell Pendants. Photograph by Helga Teiwes, Arizona State
Museum, catalogue nos. GP39336, GP9895, GP10768 and GP5765.

48 THE NAUTILUS

April 30, 1974

Vol. 88 (2)

contribute to a more thorough understanding
of the cultures which left them behind.

The carved shell ornaments come from the
Southwest, which is one of nine archaeo-
logical culture areas in North America. This
area centers on the states of Arizona and New
Mexico, spreading northward into Utah and
Colorado, and southward to encompass nearly
all of the Mexican states of Sonora and
Chihualiua (Willey: 1966, pp. 178-181; see
also Haury: 1962; Jennings and Reed: 1956).
The southeast quadrant of this area is named
after the Mogollon Mountains which lie east
of the Rio Grande, running diagonally from
Arizona into Southwestern New Mexico. To
the west of the Mogollon subarea, the Verde,
Salt and San Pedro Rivers flow into the Gila
River. The Hohokam ancestral Itmds consist
of this Lower Gila River drainage area and the
desert country to the south. North of the
Hohokam and Mogollon subareas lies Pueblo
Indian country. This third subareal division is
called by the anthropological designation
"Anasazi." There is cultural overlapping
among all three cultural subdivisions with a
pre-Historic to Historic cultural continuum
from Paleo-Indian times (ca. 14,000 B. C.)to
the present (see Rouse: 1962; Wheat: 1955;
BuUard: 1962; Martin and others: 1952).

The time period of greatest importance to
us is from about A. D. 600 to 1400 which
includes the last three phases of both the
Hohokam and Mogollon cultural traditions,
the transition from Basketmaker to Pueblo
cultural tradition in the Anasazi subarea and
the florescence of cultural habitation at Casas
Grandes in Chihuahua. Evidence from Snake-
town Ruin (Gladwan, et al.: 1937, pp.
135-153), situated north of Tucson on the
Gila River, indicates that carved shell industry
among the Hohokam during the Santa Cruz
Phase (ca. A. D. 700-900) was well in advance
of the Georgetown and San Francisco Phases
of Mogollon culture, and Pueblo I stage of
Anasazi culture. Yet, it was not until the
succeeding Sacaton Phase at Snaketown that
the carved shell industry reached a high point
at that site. The Sacaton Phase (ca. A. D.
900-1100) was the last period of Hohokam
habitation at Snaketown (see Gladwin, et al..

1937, p. 247). During the Classic stage of
Hohokam culture (ca. A. D. 1100-1400, see
Rouse: 1962, Fig. 3; Haury: 1962, Fig. 2,
gives the time period ca. A D. 1200-1500 for
the Classic stage), ornamental shell work
began to decline both in quality of work-
manship and numbers of objects.

Thirty-seven pendants and eight bracelets
carved with frog motifs comprise the initial
checklist. All the pendant specimens are
bivalve shells with the umbo pierced for
suspension. Bracelets are also bivalve shells
with frogs carved on the umbonal region and
the body of the shell ground off to form a
circular band. Six shells overlaid with
turquoise mosaic have been included with the
pendants. Three of the specimens (Fig. la and
b) are carved as well as overlaid. One is carved
with a notch on both the posterior and
anterior margins, as well as on the ventral
margin of the shell to indicate the retracted
legs and feet of a squatting frog. This
specimen is painted blue on both the
posterior and anterior sides of the convex
portion of the shell with twelve rows of
turquoise tesserae overlaid on the center
portion. In the center of the overlay, there is
a large red tessera.

The posterior and anterior margins of a
second overlaid pendant are flattened and
there is a V-shaped notch cut into the ventral
margin opposite the umbo. The turquoise
overlay covers all but the edges of the convex
portion of the shell, with four tesserae set on
either side of the notch in a manner to suggest
hind legs. A large red tessera is set in the
center of the overlay on this specimen also.
The third overlaid pendant is notched on the
posterior and anterior margins of the shell.
The overlay is in a fragmentary state, but
probably covered the entire convex portion of
the shell except for the tips of the four
flanges on the margin of the shell, which were
carved to represent frog legs and feet. There is
no CEirving on three of the mosaic ornaments.
Nevertheless, they are pendants and are
suggestive of the compact form of frogs.

Of the carved pendants without overlay,
several motif ic groups can be identified. One
motific form represents the frog with nearly

Vol. 88(2)

THE NAUTILUS

straight sides and the front and hind legs
widely separated (Fig, 2). Of the most
complete specimen, collected in the Flagstaff
area, the upper and lower portions of the legs
are well-defined and separated from the body
of the animal. Incised lines suggest the
webbed toes of the frog. A second motific
form includes specimens with more bulbous
sides. In this type, the legs are more
anatomically articulated as well as separated
from the body of the animal (Fig. 3). All four
specimens of this type at the Arizona State
Museum show that their makers were careful
in articulating the eyes. Wear, caused by
continuous handling of these ornaments,
often makes it difficult to distinguish minute
features on the pendants. In the case of these
specimens, fine quality workmanship is
evident even though they are worn down.
There is a third straight-sided type. Specimens
in this group are rather crudely carved and
lack any indication of a dorsal ridge. Two
specimens from the Arizona State Museum
are polished from cultural use, but when
compared to other well-used specimens with
carved dorsal ridges still visible, it seems that,
for this type, the dorsal ridge was never
carved. Two specimens of this type show a
distinctly flattened umbo.

One specimen is recorded with a ground-off
umbo similar to the preceding type. The
specimen is bulbous and crudely carved, and
has been assigned to a group of miscellaneous
specimens for the time being.

A group of specimens with very curved
bulbous sides is a fifth type. The legs of these
specimens are compressed to the body and
clearly incised, not carved in a rounded, more
three-dimensional manner (Fig. 4 and 5). The
toes in this type are treated as incised,
serrated projections from the legs. On one
specimen, an incised line separates the body
of the animal from the head, and the eyes are
also incised.

Five specimens are included in a sixth type.
These specimens are drilled or perforated with
holes which seem to represent eyes. Some of
the specimens are perforated at the umbo for
suspension and some are not. Some are
incised wdth geometric patterns, and some are

cut or ground off to make a lEurge perforation
in the center of the shell. One specimen
incorporates all of these motifs.

A seventh type includes specimens which
are not carved in distinct frog form. These
shells are only partially modified by grinding
along the ventral margin, and are perforated
with a large circular hole generally in the
center of the shell. They differ from type six
in that they lack drilled or perforated eye
treatment.

A triangular shell pendant was found at
Broken K Pueblo (Fig. 6) with a relief image
of a frog-like animal carved on it. The front
and hind legs are extended. The body, head
and eyes of the animal are not clearly
indicated, but the dorsal ridge is clearly
defined. Unlike the other specimens, this
pendant was made from a shell blank, a piece
cut from a larger shell. The pendants.

/ *

^Sz^S^

FIGS. 2-6 Shell Pendants (2) photograph by
Marc Gaede, Museum of Northern Arizona
catalogue no. 1545L/A5838 (3) photographs
by the author (4) Arizona State Museum (5)
catalogue nos. GP9870, GP49130 and
A25300 (6) photograph by Division of Photo-
graphy Field Museum of Natural History
catalogue no. 283703.

50 THE NAUTILUS

April 30, 1974

Vol. 88(2)

previously described, were made from an
entire valve of Glycymeris gigantea (Reeve) or
G. maculatus (Broderip) (see Gladwin, et al.:
1937, pp. 135-142; Di Peso: 1956, pp.
83-116; personal correspondence with Di
Peso: 1973; Van Stone: 1973; Dobrinski and
Hitchcock: 1973; Chaffee: 1973).

Finally, all specimens which are too worn
or fragmentary or poorly carved to be placed
in separate groups are included in a group of
miscellaneous specimens.

At the Arizona State Museum there are two
fragmentary specimens of open-work carving.
One specimen might represent a horned lizard
and not a frog because of its elongated form,
a head which is separated from the body by a
rudimentary neck, and a short tail. The other
specimen might represent a frog. Both
specimens have been carved so that the animal
motif is enclosed within the circular band of
the ventral margin. Only the hind section of
the second specimen remains so that exami-
nation of head and fore-leg features is
impossible. The hind legs are partially
extended, a feature unlike other frog
pendants from Hohokam and Mogollon
culture areas, but similiar to the triangular
pendant from Broken K Pueblo, the Anasazi
site in Northern Arizona. No tail is indicated.

The bracelets with frog images carved on
the umbonal region of the shells are less
varied in form than are the pendants. All
specimens included in the preliminary check-
list have been placed in one group. The
animals are rectangular in shape and are quite
thick (nearly as thick as they are wide). The
frog's nose is the umbo of the shell. The body
of the frog is carved from the thick umbonal
region with the front legs of the frog
compressed to the body and the feet placed
next to the head, as if the frog were grasping
the circular band of the bracelet. The hind
legs are carved as if they were overlapping the
lower portion of the body, with the heels of
the feet touching the posterior end of the frog
and the toes spread perpendicularly to the
dorsal axis. The hind leg motif takes the form
of a capital M. The remainder of the shell was
cut away except for a thick circular band,

which was the marginal circumference of the
living shell.

Frog motifs are not restricted to worked
shell. During an Arizona University expedi-
tion in 1965, a cache of carved stone and clay
objects was excavated (Ariz. U:31:l, 10-G,
Cache 1) which included two bowls. One,
carved from stone, depicts a snake devouring
a frog and one is made of clay with frog
images clinging to the outer walls of the vessel
in much the same manner as the frog images
appear to cling to the bracelets. A corrugated
clay jar from Chihuahua in the collections of
The Amerind Foundation, Inc. also incor-
porates this "clinging frog" motif.

One recurrent archaeological context for
frog pendants is evident in the initial data. Of
the forty-three carved and overlaid pendants,
twenty-eight have a known provenance. Of
these twenty-eight, ten are known to have
been associated with inhumation or cremation
burials. The age of the deceased is known in
eight of these ten burial contexts. In each of
five contexts, the pendants were buried with
the remains of children. The remaining three
were associated with young adults and are all
of the seventh motific type, i.e., pendants of
indistinct frog form (see Fig. 6). All three
specimens came from Canyon Creek Ruin, a
Salado/Hohokam transitionjil site.

Research is in progress to find and assemble
accounts of frog symbolism in American
Indian ethnology. A few legends and practices
are known which associate shells and frogs
with children and childbirth (for example, see
La Flesche: 1925, pp. 251-257). No specu-
lations regarding associations of frog pen-
dants, life and death, burial, children and
childbirth or any other extra-ornamental use
are made here due to lack of data.

Conclusions which can be drawn to date
are: one, incidence of carved shell frog
pendants is rather frequent in archaeological
contexts throughout the Hohokam and
Mogollon culture areas in the Southwest.
Two, carved shell frog bracelets are found in
the same contexts as the pendants, but with
less frequency. Three, the pendants can be
divided into several motific groups, and four,

Vol. 88 (2)

THE NAUTILUS

that when not found in association with
architectural fill and floor debris, the
pendants have been excavated most fre-
quently in connection with burials.

LITERATURE CITED

Bullard, W. J., Jr. 1962. The Cerro Colorado
Site and Pithouse Architecture in the
Southwestern United States Prior to A. D.
900. Cambridge, Harvard Univ., Peabody
Museum Papers 44(2): xii+205 pp.

Di Peso, Charles C. 1956. The Upper Pima of
San Cayetano del Tumacacori. Dragoon,
Arizona, The Amerind Foundation, Inc.
no. 7: xxiv+589 pp.

Gladwin, Harold S. et. al. 1937. Excavations
at Snaketown: Material Culture. Globe,
Arizona, Medallion Papers no. 25:
xviii+305 pp.

Haury, Emil W. 1962. The Greater American
Southwest, in Courses Toward Urban Life.
New York, Wenner-Gren Foundation for
Anthropological Research, Inc., Viking
Fund Pubhcation in Anthropology no. 32:
106-131.

Jennings, J. D. and E. K. Reed. 1956. The
Americcin Southwest: A Problem in Cul-

tural Isolation, in Seminar in Archaeology:
1955. Salt Lake City, Society for American
Archaeology Memoir no. 11: 59-127.

La Flesche, Francis. 1925. The Osage Tribe:
Rite of Vigil, in Thirty-Ninth Annual
Report of the Bureau of American
Ethnology, 1917-1918. Washington, D. C,
Smithsonian Institution: 31-630.

Martin, Paul S. et al. 1952. Mogollon Cultural
Continuity and Change: The Stratigraphic
Analysis of Tularosa and Cordova Caves.
Chicago, Chicago Nat. Hist. Museum,
Fieldiana: Anthropology 40: 507 pp.

Rouse, Irving. 1962. Southwest Archaeology
Today, in An Introduction to the Study of
Southwest Archaeology with a Preliminary
Account of the Excavations at Pecos, by A.
V. Kidder, rev. ed. New Haven, Yale Univ.:
1-53.

Wheat, Joe B. 1955. Mogollon Culture Prior
to A. D. 1000. Menasha, Wisconsin,
American Anthropological Association
Memoir no. 82: xiii-(-242 pp.

Willey, Gordon R. 1966. An Introduction to
American Archaeology. Englewood Cliffs,
New Jersey, Prentice-Hall, Inc. 1:178-245.

ADDITIONAL RECORD FOR MESODON
LEATHERWOODI (PULMONATA: POLYGYRIDAE)

Donald W. Kaufman

Department of Zoology, University of Texas,
Austin, Texas 78712

Mesodon leatherwoodi Pratt was recently
described from specimens collected at a single
locality in western Travis County, Texas
(Pratt, 1971). It is of interest to report the
occurrence of M. leatherwoodi in the
Pedernales Falls State Park, Blanco County,
Texas, which is approximately 13 miles
upstream from the type locality. Four
specimens were found near the Pedernales
Falls within 1 meter of each other at the base
of a large rock on August 6, 1972. The
collection site was above flood debris along
the river suggesting that the snails were from
the general area of the Falls, although, the

shells may have been washed down from the
oak-juniper community higher on the river
bank.

The specimens have been deposited in the
collection of the Fort Worth Museum of
Science and History (catalog number
94V-3103). W. L. Piatt verified the identifi-
cation of the specimens.

LITERATURE CITED

Pratt, W. Lloyd, 1971. Mesodon leather-
woodi, a new land snail from central Texas.
The Vehger 13(4): 342-343; 1 pit.

52 THE NAUTILUS

April 30, 1974

Vol. 88(2)

NEW FLORIDA RECORDS FOR

HYPSELODORIS EDENTICULA TA

(NUDIBRANCHIA: DORIDIDAE)

Alice Denison Barlow

5 Downey Drive

Tenafly, New Jersey 07670

The large and conspicuous chromodorid,
Hypselodoris edenticulata (White, 1952) was
originally recorded only from Dry Tortugas,
Florida. Marcus and Marcus (1967, p. 56)
gave four other records in the vicinity of Palm
Beach, Miami, Alligator Reef, and Lake
Worth, all southeast Florida, at depths from 8
to 102 feet.

On March 2, 1971, Ralph Woodring
collected a specimen in 35 to 40 feet of
water, 20 miles southwest of the Sanibel
Island Lighthouse. I maintained this specimen
for four weeks in an aquarium and made
several photographs of it. The animal was 64
mm. in length and 17 mm. in width. The
color was blue-black with brilliant
chrome-yellow markings of uneven circles and
lines with one line running unevenly com-
pletely around the outer edge of the upper
part of the body. The sole was a lavender
blue. The eleven (Marcus reports 10, and
White 9), branchial plumes were outlined in
chrome-yellow, with a yellow line running
down the center of each plume, with diverse
yellow spots on either side. The secondary
pinnules on the plumes were lavender; the
rhinophores blue-black. White (1952, p. 114)
records that the vermilion spawn is laid on the
alga, Caulerpa prolifera.

In the Spring of 1971, Mr. Russell Jensen
of the Delaware Museum of Natural History
sent my photographs to Mr. Gale Sphon of
the Los Angeles County Museum of Natural
History who kindly identified them as
Hypselodoris edenticulata (White), with the
suggestion that this gives a further range for
the animal that should be noted in the
literature.

In October, 1973, I wrote Mr. WiUiam G.
Lyons of the Bureau of Mzirine Science and
Technology Florida, for any information he
might have on the species. He very kindly
gave much additional information:

"Hypselodoris edenticulata (White) is
perhaps the most common large nudibranch
offshore along the Florida west coast. In any
event, it was the most frequently collected
during Project Hourglass, our 28-month study
of the fauna on the central west Florida shelf.
In addition, I have seen many specimens
brought in by divers from as far north as
Tarpon Springs. Like your specimen, all I
have seen from the Gulf coast are from 30-40
ft. depths out to some as great as 180 ft.
Specimens are occasionally taken along the
lower east coast of Florida in estuaries where
tropical conditions prevail. 1 have taken them
for several years in the Indian River near the
St. Lucie Inlet, Martin County, but only when
conditions allow intrusion of many other
tropical species."

LITERATURE CITED

Marcus, Eveline and Ernst Marcus. 1967.

American Opisthobranch Mollusks. Univ.

Miami, Florida. 256 pp.
White, Kathleen M. 1952. On a Collection of

Molluscs from Dry Tortugas. Proc. Mai.

Soc. London 29(2-3):106-120.

FIG. 1. Hypselodoris edenticulata (White,
1952) from Sanibel Island, Florida, in 35-40
feet of water. Length: 64 mm. Lower view
shows details of gills (photos by A. D.
Barlow).

Vol. 88 (2)

THE NAUTILUS

FURTHER NOTES AND CORRECTIONS CONCERNING THE

SPAWN OF FLORIDA CYPHOMA (OVULIDAE)

M. Ellen Crovo

2915 S.W. 102 Avenue

Miami, Florida 33165

ABSTRACT

The oothecae, manner of capsule deposition, and the operculate veligers
of Cyphoma gibbosum (Linne) from Florida are described. Observations
made by Harding B. Owre on the spawn of C. macgintyi are published. The
egg capsule illustrated by Gather and Crovo (1972, The Nautilus 85(4): 113)
is now believed to have been that of an Anachis (Columbellidae).

Conflicting accounts of the nature of the
oothecae of Cyphoma gibbosum have recently
been published (Gather and Crovo, 1972;
Bandel, 1973; Ghiselin and Wilson, 1966). It
now appears that the ootheca illustrated in
The Nautilus (85(4): 113, fig. 1) by Gather
and Crovo is not that of Cyphoma, but rather
an egg capsule of a columbellid snail, most
closely resembling that of Anachis avara
(illustrated by Scheltema, 1968, p. 5, text fig.
2) and Anachis sp. [catenata?] (illustrated by
Raeihle 1969, p. 26, fig. 2). Cather (in litt.)
believes his error may be due to the
undetected presence in his aquarium of a
columbellid near the base of the sea fan.

Further recent observations by the author
substantially confirm the accounts of Cypho-
ma oothecae by Bandel (1973) and by
Ghiselin and Wilson (1966).

On November 9th, 1969, four living
specimens of Cyphoma gibbosum (Linne)

FIG. 1. Egg capsule of an Anachis from
Bermuda, erroneously identified as Cyphoma
gibbosum in The Nautilus, vol. 85, p. 113,
1972.

were placed in a five gallon saltwater
aquarium. Eleven days later, on November 19,
one snail was observed working over a
three-inch-square area of glass an inch below
the surface of the water. On the morning of
November 20 a network of 23 flexible,
translucent capsules containing minute white
eggs was formed. These capsules were
approximately 2.0 x 2.1 mm.,
irregularly-placed rather than in even rows.
Each capsule had a very short, indistinct,
slotlike hatch at one end.

Each morning the mollusk returned to her
laying area, adding to it until the last of 73
capsules was laid by late evening of November
24. The mother remained close to the mass of
capsules, returning each morning, carefully

FIG. 2. Egg capsules of Cyphoma gibbosum
(Linne), both empty and full, laid on a
denuded section of a seafan from Florida.
Photo courtesy of R. T. Abbott (greatly
magnified).

54 THE NAUTILUS

April 30, 1974

working over the area for a period of three to
four hours.

Five days after formation of the capsules
active embryos were observed within the
capsule walls. Ten days later, the capsules
became a light flesh-pink color, gradually
darkening to a deep-rose as the veligers grew
to full size. On the fifteenth day the
free-svnmming veligers began to escape
through a newly-formed slit on the top of
each capsule. Without proper food and
environment the veligers died after a few
days. By carefully opening one capsule wath a
sharp needle, it was found to contain about
1270 veligers.

Similar observations v«th other egg-laying
Cyphoma gibbosum were made in August,
1972. One small male and four larger female
Cyphoma were collected from one Gorgonia
ventalina Linne 1758. Each female laid her
eggs in a separate area on the same Gorgonia,
and all produced their capsules within five
days. It was noted that warmer room and
water temperatures reduced incubation time
by 36 to 72 hours. We were also successful in
obtaining photographs and measurements of
capsules and veligers. The average size of the
latter was 0.153 mm. The number of capsules
and veligers varies according to the size of the
producing adult Cyphoma. The veliger count
of one full capsule in this series was 780.
Adults were several millimeters smaller than
those observed in November. Veligers from
one capsule lived in a petri-dish of seawater
for nine days with no attention other than
daily checks on their activity. A tiny
operculum is clearly visible on the Cyphoma
gibbosum veligers, but this organ evidently is
lost during metamorphosis.

The following account of the spawn of
Cyphoma macgintyi Pilsbry and the accom-
panying drawings were kindly supplied by Dr.
Harding B. Owre of Miami, Florida, and were
taken from her unpublished Master's thesis
(1949, pp. 24-25):

Cyphoma macgintyi "is generally found on
an alcyonarian, where it feeds by sucking up
polyps as it crawls along a branch. It deposits
its spawn on a portion of a branch which has
been cleared of polyps. Although it is

Vol. 88 (2)

FIG. 3. Veliger of Cyphoma gibbosum
(Linne) showing shell, soft parts and oper-
culum (greatly magnified).

,-\^7i^'^^^''^^^^X^0(k'^'^^.

Sd^'J^uj^K^'t^ - -'^^-i?

FIGS. 4-6. Cyphoma macgintyi Pilsbry from
Soldier Key, Florida. 4 and 5, preveligers. 6,
oothecae on a stem of alcyonarian. (drawings
by Harding B. Owre).

probable that the adults lay eggs at other
seasons, spawn has not been found except in
the spring.

"Two egg masses were collected on April
10, 1948, in the alcyonarian bed on the ocean
side of Soldier Key. In both cases, the spawn
was laid on Eunicea multicavda, which was
growing in water about four feet deep. An
adult, presumably the parent, was found on
each branch with the spawn. The maintenance
of the spawn in the laboratory was difficult,
for it could not, with safety, be separated
from the cut branch of Eunicea, and the latter
survived only two days.

"The spawn is laid out in an area which is

Vol. 88(2)

THE NAUTILUS

roughly rectangular, about 12 cm long and 1
cm wide. The mass is composed of numerous
variously-shaped cases, which are gelatinous,
thin, and flat or faintly convex on the upper
side. In one mass, there were 111 cases, each
one measuring approximately 4.5 x 4.0 x 1.0
mm. There are about fifty minute embryos in
each case. The color of the spawn varies from
white to pale pink, becoming a darker pink as
the young mature.

"When collected, the young were late
trochophore larvae. By April 13, 1948, the
Eunicea had disintegrated to such an extent
that the larvae in some of the cases were dead
and it was necessary to release the rest. The
"hatching" was premature, for the veliger
stage had not quite been reached, and the
larvae did not survive.

"The pre-veliger had a colorless translucent
shell of one whorl. The diameter was about
0.12 mm. The heavily ciliated velum was still
a single lobe with an extension on either side
and one in the middle. There was a tuft of
especially long cUia, remaining from the
prototroch, on each projection. The foot was
ciliated. The eyes and tentacles had not yet
appeared."

ACKNOWLEDGEMENTS

I wish to thank Dr. Harding B. Owre for
her interest and advice on photographing the
Cyphoma gibbosum veligers and the use of
her equipment. I am also indebted to her for
the additional information which she gener-

ously shared with me on Cyphoma macgintyi
from her studies for her Master's thesis. I
would also like to thank R. Tucker Abbott
for his editorial assistance and for the
photograph of the oothecae of Cyphoma
gibbosum.

LITERATURE CITED

Cather, J. N. and M. E. Crovo. 1972. The
Spawn, Early Development and Larvae of
Cyphoma gibbosum (Cypraeacea). The
NautUus85(4):lll-114.

Bandel, Klaus. 1973. Notes on Cypraea
cinerea Gmelin and Cyphoma gibbosum
(Linnaeus) from the Caribbean Sea and
Description of their Spawn. The Veliger
15(4):335-337.

Ghiselin, Michael T. and Barry R. Wilson.
1966. On the Anatomy, Natural History,
and Reproduction of Cyphoma, a Marine
Prosobranch Gastropod. Bull. Marine
Science 16(1):132-141.

Owre, Harding B. 1949. Larval Stages of
Some South Florida Marine Gastropods.
Master's Thesis, Univ. Miami, Florida; pp.
24-25.

Raeihle, Dorothy. 1969. Egg Cases of
Nitidella ocellata Gmelin and an Anachis.
Annual Report for 1969, Amer. Mai.
Union, pp. 25-26.

Scheltema, Amelie H. 1968. Redescriptions of
Anachis avara (Say) and Anachis translirata
(Ravenel) with Notes on Some Related
Species (Prosobranchia, Columbellidae),
Breviora, no. 304, pp. 1-19.

VIVIPARUS MALLEATUS IN MONTREAL, CANADA

Dominique A. Bucci

320 91st Street, Chomedy,
Laval, Quebec, Canada

Heretofore, the most northerly record for
the freshwater gastropod, Viviparus malleatus
(Reeve), has been New Hampshire (Perron
and Probert, 1973, The Nautilus 87(3):90). In
the summer of 1973 I found this species
abundant in one to two feet of water in a

small lagoon in the public park at Cartierville,
Montreal Island, Quebec. During the fall and
wdnter, adults move to deeper water. Speci-
mens have been deposited in the Delaware
Museum of Natural History.

56 THE NAUTILUS

April 30, 1974

Vol. 88 (2)

THE INTRODUCED ASIATIC CLAM, CORBICULA,

IN CENTRAL ARIZONA RESERVOIRS

John N. Rinne'

Research Associate

Department of Zoology and Lower Colorado River

Basin Research Laboratory

Arizona State University

Tempe, Arizona 85281

ABSTRACT

Horizontal and vertical densities and biomasses of Corbicula in two central
Arizona reservoirs were estimated employing meter square quadrats and
Ekman dredge sampling. Concentrations of clams increased with depth of
water and down-lake from inflow areas characterized by greater turbidity
(suspended sediment). Densities were highest on rock-rubble slopes and
increased directly with complexity (number of components) of substrate.
Data suggest food supply, substrate, turbidity and perhaps fish predation as
important factors in determining densities and biomasses of clams in the two
reservoirs examined.

INTRODUCTION

Corbicula was first recorded in Arizona in
1956 from the Phoenix CEinal system (Dundee
and Dundee, 1958). Introduction into
Arizona, possibly from CEilifornia, most likely
occurred by man in the role of tourist,
fisherman, or aquarium hobbyist. It was first
recorded in abundance in the Southwest from
the Coachella Valley, California, in 1953
(Ingram, 1959). In 1963, Corbicula had
re-invaded irrigation systems of the Colorado
River Indian Reservation eifter its eradication
a year earlier (Ingremi, et al., 1964). Since that
time it has spread throughout the entire lower
Colorado River basin. The rapid spread of this
animal upon introduction at various localities
in the United States led Sinclair (1971) to
describe Corbicula manilensis as " . . .
currently the most costly liability of all exotic
molluscs in North America . . ." This "pest"
currently inhabits the Salt River reservoir
system, central Arizona, where it occurs most
abundantly in Roosevelt and Apache lakes
(Fig. 1) Corbicula are scarce in the lower two
reservoirs. Canyon and Saguaro lakes, for
which I have no explanation since they are

abundant upstream, and downstream in the
Salt River between Stewart Mountain and
Granite Reef dams and in the Phoenix canal
systems. Locally, they comprise a major
component of the benthic fauna of the upper
two reservoirs.

METHODS AND MATERIALS
Corbicula were collected sporadicEilly from

TOKTO CRCEK r^FLOH

Y^"-* (WOSEVELT UK£

'Current Address: EAFFRO, P. O. Box 1881,
Kisumu, Kenya

FIG. 1. The two most upstream lakes,
Roosevelt and Apache, of the Salt River
system of reservoirs showing transect loca-
tions and place names used in text.

Vol. 88 (2)

THE NAUTILUS

Roosevelt and Apache lakes (Fig. 1) in
November 1970, 1971 and February 1972.
Almost all specimens were collected in a
moribund state, or dead, on exposed lake
shore during low-water conditions. Several
meter-square {m2) quadrats were randomly
thrown at a given site. All clams within this
area with hinges yet attached were collected,
and retained for later examination. In some
cases intact valves would break upon
handling, or were parted when later examined
and measured. In either instance, these were
counted. No specific information concerning
time required to sufficiently decompose
hinges and promote separation of valves was
available to me. This undoubtedly varies with
conditions following death. Most collections
were made after a drop in reservoir level and
consisted predominantly of individuals which
had died of desiccation. Time-lapse between
collection and exposure to drying varied in all
cases, and could, indeed, affect density
estimates. Autumn 1970 collections in Roose-
velt and Apache were both within a month
after the substrate was exposed by receding
water. The November 1971 sampling in
Roosevelt at R-1 was performed near water
line and specimens were most likely exposed
for only 2 to 3 months. By contrast,
November 1971 and February 1972 collec-
tions in Apache were subject to approxi-
mately 7- to 10-month exposures, respec-
tively, and sampling across from Frazier's
Landing (equidistant between R-2 and R-3,
see Table 2, Fig. 1) was undertaken on
bottom that had been dry for more than a
year. Other shortcomings of such collecting
techniques were alteration of information by
predatory mammals and birds, and activities
of man. The last was circumvented to a large
extent by selecting sites away from human
activities.

Clams were measured (widths) and counted
in the laboratory. Live clams were processed
to determine dry and ash-free dry weights of
animals excluding the valves. Regression
analysis of size and weight indicated a power
function giving the highest r-value (+0.98;
equation: y = [0.0110608] x X 3.0129).
Mean size of all Corbicula within a quadrat

was employed to estimate approximate
biomass per unit area using the plotted
regression line.

RESULTS

Two, shallow-to-deep-water transects at
arbitrarily selected locations in Roosevelt and
Apache lakes were sampled to determine the
possible effect of depth of water on densities,
sizes, and biomasses of Corbicula. Both
transects generally indicated an increase in
numbers and biomasses of clams with
progression to deeper water (Table 1; Fig. 1),
depending somewhat on substrate. Sampling
in approximately 3.4 meters (m) of water on
the north shore of Roosevelt Lake yielded no
clams on rubble bottom. At deeper, down-
slope sites, the animal became progressively
more dense. Substrate along this transect was
generally rocky. However, diversity of the
habitat, increased directly with increasing
depth. Shallower sites were far more uniform
in sizes of substrate components, whereas at
deeper levels, sand, rubble, gravel and
boulders were interspersed. Average sizes of
clams neither consistently, nor significantly,
changed with depth.

The transect near A-2 (Burnt Corral, see
Figs. 1 and 2) was located on an extremely
steep, rock-covered slope, with the exception
of several m" quadrats sampled on mud-sand
flats. Numbers of clams were low at a depth
of 2.2 m on sand-silt substrate (Table 1).
Quadrats at 3.4 m were located near the crest
of a rock slope (approximately 26% grade).
Numbers and biomasses of clams then
increased dramatically, remaining high to a
depth of 18 m, where a drastic decrease in
density occurred. The last site (BC-1-5) was
located at the base of the rocky slope and was
composed of sand-gravel substrate. Four
quadrats were sampled on sand-gravel sub-
strate, lying upon the old river terrace
immediately below the rocky slope. Numbers
cdso were extremely low in this area (BC-4-1).
Several more quadrats were sampled at 20 and
22 m below full lake level (BC-2-1 and
BC-3-1), on a second rocky slope, which
dropped toward the old river channel.
Densities of clams increased over those on the

58 THE NAUTILUS

April 30, 1974

Vol. 88 (2)

lABlE I. AVERAGE SIZES, DENSITIES, A«) BIOHASSES OF COBBICULA AT SHALLOH-TO-OEEP-WATER TRANSECTS IN ROOSEVELT A«)

APACHE

LAKES. HArCES ARE

StOKN IN

( ).

TRANSECT

jEPTM

BELOW r.

..uhSTRAIf.

A.tiWii

NUMBER /M^

BIOMASS

DESCRIPTION

POOL WATER MARK

(M)

SIZE (mm)

KE/HA

apacme lake

(BURNI CORRAL)

BC-I-I

2.2

Sand-Si IT

19.6(7-38)

7.0(5-9)

6.0

BC-l-2

3.4

Rubble

19.7(5-57)

208.0(27-367)

181.0

EC- 1-3

9.0

Rubble

22.5(5-38)

383.0(221-589)

482.6

ec-i-4

13. 4

Rubble

19.8(3-38)

380.0(240-499)

338.2

BC-l-5

18.0

Gravel-sanO,
stnal 1 rubble

22.5(10-38)

25.0(20-29)

31.5

BC-4-1

17.0

Sand-gravel

25.0(19-28)

3.0(5-9)

5.4

ac-3-i

22.0

Rubble

14.5(6-28)

32.0(0-64)

9.9

EC-2-1

20.0

Sand-rubble

18.4(7-28)

17.0(0-34)

12.2

ROOSEVELT LAKE (NORTH SHORE EQCJ IDI STANT BETWEEN R-2 Mt> R-3)
F-50 3.4

F-lOO 7.0

F-150 10.4

F-200

14.0

Rubble

0.0

Rubble

13.8(5-25)

22.0(12.3)

Sand-gravel

20.2(8-36)

124.0(86-166)

Sand, gravel ,

19.2(8-32)

176.0(121-163)

rubble, boulder

higher terrace, however, they were far lower
than those on the shallower, rocky slope. Mud
flats near this locality, despite excavation to
depths of 0.5 m yielded no indications of
clams.

Another shallow-to-deep transect similar to
those discussed above was sampled in the
vicinity of R-4 (Fig. 1) on a predominantly
silt slope containing little rock or sand. Eleven
m^ quadrats were examined — seven con-
tained no clams, three had 2, and one had 3
clams. Two quadrats at approximately 15 m
below high waterline contained only 2
clams/m' . Two samples from about 17 m of
water contained only 2 and 3 clams/m^ .
These data also support the evidence for
greater densities in deeper water and on
rock-rubble slopes.

Variation in average sizes, numbers, and
weights per unit area of all Corbicula
collected in areas as near to established
transects as possible in Roosevelt and Apache
lakes are in Table 2. No consistent trends in
average sizes of clams were detectable among
localities in Roosevelt Lake. Greater biomass,
however, was present at down-lake transects
(e.g. R-2). Densities of clams at about a
kilometer (km) east of R-2 and on the north
shore of Roosevelt roughly equidistant
between R-2 and R-3, were 2 to 6 times the
mean densities, and 4 to 10 times the
biomasses recorded nearer inflow areas.
Evident harvesting of clams by humans at
Frazier's landing, a major boat launching area,
was reflected in drastically lower densities
(Table 2). Considering all quadrats sampled in

Vol. 88 (2)

THE NAUTILUS

T*BLt 2. AVERAGE SIZES, NUMBERS, UNO BIOHASStS OF CORBICULA AT SELECTED LOCALITIES IN ROOSEVELT AND APACHE LAKES.
RANGES ARE SHOWN IN ( J.

LAKE

LOCALITY

AVERAGE SIZE

Cmm)

BI0MA5S
< KG/HA

ROOSEVELT

R-l 11.4(10.1-13.7)

I km. E. R-2 14.7(10.0-18.5)

Frazier's Landing

21.8(18.8-27.8)

N, shore of Roosevelt

equidistant from R-2 and R-3 18.6(14.2-20.9)

53.0(12.0-103.0)

I 19.0(42.0-243.0)

19.0(52.0-243.0)

I 10.0(32.0-243.0)

10.0(1.4-14.0)

45.0(10.7-87.5)

I 10.0(10.6-137.8)

110.0(10.6-137.6)

0.5 Wn. N. A-2

25.9(23.5-29.0)

20.6(10.5-27.9)

20. 8( 17.2-25.9)

19.4(11.5-23.8)

26.0(11.0-59.0)
177.4(5.0-589.0)
73.0(14.0-166.0)
65.0(30.0-152.0

49.9(35.9-105.6)
194.1(0.65-1,060.0)
68.9(18.2-164.3)
56.2(11.4-214.0)

Roosevelt Lake, numbers of clams ranged
from 12 to 243 /m^ , and biomasses from 1.4
to 137.8 kilogram per hectare (kg/ha).

Average size, density, and biomass of clams
generally decreased downlake in Apache
(Table 2). Great variation in these parameters
at two sites, one at A-2 and another less than
a km north, reflects the influence of bottom
type on clam populations (Table 2). At A-2,
the substrate consisted of compacted gravel,
and clams were scarce; however, in
boulder-strewn slopes, up-lake Corbicula were
almost eight times as numerous per unit area
(Table 2). Furthermore, three sets of adjacent
samples taken in February 1972 on
rock-boulder (in contrast to the sand-gravel
substrate at A-3 in Apache Lake— (Fig. 3)
yielded significantly greater densities in all
cases in the former, ranging from 2.5 to 9.0
times higher (66-25, 121-14, 38-8) than in
A-3's sand-gravel substrate type.

Over-all, densities of Corbicula in Apache
Lake ranged from 5.0 to almost 600/m^ , and
standing crops from 0.65 to 1,060 kg/ha,
excluding weights of shell. Analysis of

variance showed non-significant differences
between numbers, sizes, and biomasses
relative to depth at all transects and in
comparison of samples from the two localities
at A-2.

Meager data on Corbicula were obtained
from Ekman dredge samples (Table 3). Few
clams occupied the soft, fine-grained sedi-
ments that the Ekman dredge sampled most
efficiently. Numbers of live clams taken in
Ekman dredge samplings were comparable to
those collected in meter square quadrats. For
example, 5 of 20 Ekman samples taken at
A-2, in Apache Lake indicated clam densities
of 43 to 86/m^ (Table 3), compared to
26/m^ estimated by the quadrat method
(Table 2). Densities of clams at A-5 estimated
by these same two sampling methods, also
were comparable (Tables 2 and 3).

DISCUSSION

Data from Roosevelt and Apache Lakes
were not significantly different at the 0.05
level in either biomasses or numbers of clams
between lakes or in most cases, among

VAUTI]

.US

April 30, 1974

Vol. 88 (2)

TUBLE 5.

5U»«ARY QF

COfiBlCULA COLLECTED krl

TH AN EtWAr. DREDGE IN APACHE

LAKE,

1971.

TRAHSECT,

STATION

DATE

NUMBER COMTAINING

NUMBER/DREDEING

ESTIMATED

CORSICULA

MUMBER/M^

»P»CME

»-2-l

3-30-7 1

3 o* 8 dredgings

43.0

A-2-5

3-29-7 1

1 0* 10 dredgings

ae.o

A-2-3

3-30-71

I of 2 dredgings

86.0

*-5-l

3-23-71

1 of 8 dredgings

172.0

A-4-3

3-22-71

2 of 10 dredgings

1
2

43.0

86.0

A-5-1

3-22-71

3 of 15 dredgings

86.0

43. C

transects, but actual values of each of these
seemed to vary inversely up- to down-lake,
when the two reservoirs were compared.
Inflow areas of Roosevelt Lake were more
turbid, and normally had more phyto-
plankton as indicated by chlorophyll-a data
(Portz, 1973; Rinne, 1973). As given above,
clams were far more dense down-lake from
inflow areas in Roosevelt Lake. The effect of
greater inorganic suspended solids at the Salt
River inflow of Roosevelt may well have
suppressed the population of clams, despite
an adequate food supply.

By comparison, densities and biomasses of
Corbicula decreased down-lake in Apache
Lake in presence of both sparser food and less
turbidity relative to that recorded in up-lake
sectors. These data indicate that food supply
may be more limiting to Corbicula than
turbidity. Prokopovich (1969) recorded de-
creases in densities of clams downstream in
the Delta-Mendota Canal, California, and
attributed this to decreasing food supply.
However, turbidity as a factor in affecting
dispersion of clams can not be eliminated as
indicated by my data and that of others. A
high mortality of Corbicula in the Ohio River
in spring was attributed to increased tur-
bidities (more than 400mg/l) by Bickel
(1966).

Vertically, densities of Corbicula seemed to
increase with depth, modified somewhat by
bottom type and location within the reservoir
system. This may be an indication of the
influence of food supply (phytoplankton) as
effected by photic conditions (Portz, 1973;
Rinne, 1973). In addition, rocks and boulders
upon slopes vnthin these two reservoirs
provide protection for juvenile clams from
predators. Several species of fishes; carp
(Cyprinus carpio Linnaeus), smallmouth (Icti-
obus bubalus [Rafinesque] ) and black ('/c^i-
obus niger [Rafinesque]) buffalofishes
consume large numbers of Corbicula
(Minckley, et al., 1970; Rinne, 1973).
Increase in densities of clams with depth may
therefore be a reflection of greater fish
predation in shallower areas of the lake.

Corbicula is knovra to remove suspended
orgEinic and inorganic particles from water
and deposit them as pseudofeces (Proko-
povich, 1969). Heinsohn (1958) reported two
to three small Corbicula were capable of
clearing 500 milliters of "very turbid water"
in less than 2 minutes. Precipitation of
plankton from aquatic media by Corbicula
was reported by Greer (1971), and laboratory
studies at Arizona State University suggested
filtration rates are directly related to concen-
tration of algal cells in solution (Richard

Vol. 88(2)

THE NAUTILUS

Stephenson, pers. comm.). Above certain
critical concentrations of algal cells, clams
began indiscriminantly to precipitate food
and inorganic particles, presumably to clear
their gUls and thereby prevent asphyxiation.
Ideal conditions for Corbicula seemingly
would include both clear waters and adequate
food supply. Large concentrations of this

FIG. 2. Photograph of a rock-rubble slope
typical of central Arizona reservoirs (A) and
closeups (B and C) showing complexity of
these habitats and interstices providing
protection for clams from fish predation.

clam downstream from hydro-electric dams
has been attributed to clear, plankton-rich
waters (Heard, 1964), 1 noted the greatest
concentrations of clams (1,500/m^ ), in the
canal below Granite Reef Dam where both
clear water and adequate food were present.
LITERATURE CITED

Bickel, D. 1966. Ecology of Corbicula
manilensis Philippi in the Ohio River at
Louisville, Kentucky, Sterkiana 23: 19-24.

Dundee, D. S., and H. A. Dundee. 1958.
Extensions of known ranges of 4 mollusks.
The NautUus 72: 51-53.

Greer, D. E. 1971. Biological removal of
phosphates from aquatic media. Unpub-
lished M. S. Thesis, Univ. of Arizona,
Tucson, 29 p.

Heard, W. H. 1964. Corbicula fluminea in
Florida. The Nautilus 77: 105-107,

Heinshohn, G. E. 1958. Life history and
ecology of the freshwater clam, Corbicula
fluminea. Unpublished M. S. Thesis, Univ.
of California, Santa Barbara. 64 p.

Ingram, W. M. 1959. Asiatic clams as
potential pests in California water supplies.
Jour. Amer. Water Works Assoc. 51:
363-370.

Ingram, W. M., L. Keup, and C. Henderson.
1964. Asiatic clams in Parker, Arizona. The
Nautilus 77: 121-124.

Minckley, W. L., J. E. Johnson, J. N. Rinne,
and S. E. Willoughby. 1970. Foods of
buffalofishes, genus Ictiobus, in central
Arizona reservoirs. Trans. Amer. Fish. Soc.
99: 333-342.

Portz, D. E. 1973. Plankton pigment hetero-
geneity in seven reservoirs of the lower
Colorado basin. Unpublished M. S. Thesis,
Arizona State Univ., Tempe. 168 p.

Prokopovich, N. P. 1969. Desposition of
clastic sediments by clams. Jour. Sedi-
mentary Petrology 39: 891-901.

Rinne, J. N. 1973. A limnological study of
central Arizona reservoirs with reference to
horizontal fish distribution. Unpublished
Ph.D. Thesis, Arizona State Un.v., Tempe.
350 p.

Sinclair, R. M. 1971. Annotated bibliography
on the exotic bivalve Corbicula in North
America. Sterkiana 43: 11-18.

62 THE NAUTILUS

April 30, 1974

Vol. 88 (2)

MICROSTRUCTURE OF CHALKY DEPOSITS FOUND IN SHELLS
OF THE OYSTER CRASSOSTREA VIRGINICA'

Stanley V. Margolis

Department of Oceanography,

University of Hawaii

Honolulu, Hawaii 96822

and Robert E. Carver

Department of Geology

University of Georgia

Athens, Georgia 30602

ABSTRACT

Scanning electron microscopy has revealed that chalky deposits in shells
of Crassostrea virginica consist of blade-shaped crystals of calcite oriented
perpendicular to the inner surface of the shell. From a structural standpoint,
these chalky deposits appear to represent a layer of calcite which is a
morphologically distinct entity, and not merely a porous and disoriented
variant of the calcite ostracum. Chalky deposits are common at all stages of
growth and are irregularly distributed across the inner surfaces of the valves.
It is suggested that deposition of calcite in the form of chalky deposits
occurs as a specific physiological response to environmental stimuli, possibly
during periods of maximum respiration.

The shell of Crassostrea virginica, the
common commercial oyster of the Atlantic
coast of North America, has been described as
consisting of two layers of crystalline calcite
with a thin, to absent, outer organic
periostracum (Galtsoff, 1964). Our exami-
nation of various portions of fresh C. virginica
valves by scanning electron microscopy has

'Contribution number 594, Hawaii Institute of
Geophysics

revealed that the outer crystalline layer is
composed of elongate, prismatic calcite
crystals oriented perpendicular to the shell
wall and enmeshed in a reticulum of
conchiolin which separates and defines the
individual calcite prisms (Fig. lA). The
electron micrographs shown here represent
specimens which first were cleaned of
adhering organic material with a 5% sodium
hypochlorite solution, and then etched
briefly in a 10% solution of acetic acid in
order to bring the crystal structure out in

FIG. 1 (opposite page)

A. Cross-section of outer crystalline layer of
C. virginica showdng elongate calcite crystals
oriented perpendicular to outer shell surface.
Conchiohn has been partially removed by
sodium hypochlorite.

B. Cross-section of inner calcite ostracum
layers consisting of thin sheets oriented
parallel to inner surface of shell.

C. Fractured portion of inner calcite ostracum
illustrated in B showing structure of calcite
sheets.

D. Etched cross-section of hinge area of C.
virginica shovnng thick inner calcite ostracum

(O) and thinner interbedded discontinuous
chalky layers (C).

E. Interface between chalky layer (upper
portion of photo) and calcite ostracum (lower
portion) showing different orientation and
morphology of crystals.

F. High resolution photo of chalky layer
showing aggregates of blade-shaped crystals.
Clumpy material adhering to crystals are
remnants of conchiolin which had been
incompletely removed by sodium hypo-
chlorite.

Vol. 88 (2)

THE NAUTILUS

7*'<k'>vV>>^.lOii

FIG. 1. Microstructure of Oyster Shell, Crassostrea virginica
(explanation on opposite page)

64 THE NAUTILUS

April 30, 1974

Vol. 88(2)

relief. The inner layer of calcite is much
thicker than the prismatic layer and consists
of thin blocks, or sheets, of calcite oriented
with the long axes parallel to the inner surface
of the shell (Figs. IB, C). In the inner layer,
or calcite ostracum, as in the prismatic layer,
each calcite crystallite is completely sur-
rounded by a thin membrance of conchiolin
(Watabe et al., 1958). Stenzel (1963) found
that the hypostracum, the crystalline material
of the areas of attachment of the adductor
muscle imprint of Quenstedt's muscle, con-
sists of aragonite, rather than calcite. We also
noted slender aragonite crystals in our
examination of the hypostracum.

The most intriguing aspect of the shell
structure of C. virginica and other species of
Crassostrea is the almost universal occurrence
of patches of dead-white, porous material
called "chalky deposits" on the interior
surface of the shell. Chalky deposits also
occur within the body of the shell, inter-
layered with calcite ostracum (Figs. ID, E),
indicating that they represent temporary
phenomena, deposited at some time, when
overgrown by the more abundant calcite
ostracum. Galtsoff (1964) studied the mor-
phology and distribution of chalky deposits in
C. virginica and found that they are randomly
distributed over the inner surface of the shell
and do not appear to be related to either
injury or senility. Medcof (1944) and
Korringa (1951) had previously suggested that
chalky deposits serve to correct the internal
volume and curvature of the shell to conform
to body size and shape, but Galtsoff found no
evidence to support this view.

We report that examination of the "chalky
deposits" show them to consist of
blade-shaped crystals of calcite oriented
perpendicular to the inner surface of the shell.
The structure is not porous nor a disoriented
phase of the normal calcite-ostracum struc-
ture, as has been previously thought, but an
entirely different, perhaps physiologically
unique, structure. "Chalky deposits" consist
of aggregates of blade-shaped calcite crystals
(Figs. IE, F) oriented with long axes
perpendicular to the inner surface of the shell.
Intermediate axes of neighboring crystals tend

to be oriented subparallel to the plane of the
shell surface, establishing crystal domains
consisting of 5 to 20 similarly oriented calcite
crystals. "Spurs" extending from the long
axes of calcite crystals at approximately 60°
(Fig. IF) suggest that the long axes are
parallel to the c crystallographic axis of
calcite, the intermediate axes parallel to a.
The etching treatment was desirable in
revealing the internal structure of the chalky
deposits, although it somewhat blunted and
pitted individual crystallites. Further exami-
nation of specimens etched to a lesser degree,
revealed that the crystallites and spurs are
smooth-walled and sharp-edged, and that
spaces between crystals are filled with
conchiolin.

The contrast in orientation and mor-
phology between the crystals of the calcite
ostracum and the "chalky deposits" (Figs.
lA, B) suggests that the "chalky deposits"
perhaps represent selective growth by the
oyster of these discontinuous layers as a
physiological response to one or several
environmental stimuli. Furthermore, the irreg-
ular distribution of "chalky deposits"
throughout the body of the shell and across
the inner surface of the shell described by
Galtsoff (1964) indicates that the process of
formation of chalky deposits is highly
irregular vnth respect to growth stages of the
organism, and with respect to time. Although
unknown, the environmental stimuli involved
are probably factors which experience episo-
dic fluctuations, and we can draw on the
experience of Dugal (1939) for a possible
analogy.

Dugal (1939) found that C. virginica and
Mercenaria mercenaria (Veneridae) resorb ma-
terial during anerobic metabolism resulting
from long periods of shell closure, smd that
the resorption buffers a potential decrease in
pH of body fluids basically attributable to
accumulation of CO^ in fluids of the body
cavity. The Dugal effect, resorption of shell
material to buffer a low body-fluid pH, may
be the exact opposite of the physiological
process leading to the accumulation of chalky
deposits. It may be possible that during
periods of maximum ventilation, the CO^

Vol. 88(2)

THE NAUTILUS

content of the body fluids decreases, with a
consequent increase in pH. Elimination of
calcium from the body fluids at this stage by
decreasing the CaCOa saturation would tend
to reduce pH and buffer the effect of excess
ventilation. We suggest that this type of
calcite deposition is physiologically different
from that of normal shell growth, and might
explain the morphologic difference between
the chalky deposits and the calcite ostracum
layers.

ACKNOWLEDGEMENTS

The authors would like to thank Richard
Young for helpful suggestions. This research
was supported by N.S.F. grant GD-34270 for
the establishment of the Scanning Electron
Microscope Laboratory at the University of
Hawaii.

LITERATURE CITED
Dugal, L. P. 1939. The use of calcareous shell

to buffer the production of anaerobic
glucosis in Venus mercenaria. Jour. Cell.
Comp. Physiol. 13 (2): 235-251.

Gaitsoff, P. S. 1964. The American Oyster.
Fish. Bull. Fish Wildlife Serv., 64: 1-167.

Korringa, P. 1951. On the nature and
function of chalky deposits in the shell of
Ostrea edulis Linnaeus. Proc. Calif. Acad.
Sci., Ser. 4, 27: 133-159.

Medcof, J. C. and Needier, A. W. H. 1944.
The influence of temperature and salinity
on the condition of oysters (Ostrea
virginica). Jour. Fish. Res. Bd. Canada 6
(3): 253-257.

Stenzel, H. B. 1963. Aragonite and calcite as
constituents of adult oyster shells. Science
142: 232-234.

Watabe, N., Sharp, D. G. and Wilbur, K. M.,
1958, Electron microscopy of crystal
growth of the nacreous layer of the oyster
Crassostrea virginica. Jour. Biophys. Bio-
chem. Cyt. 4: 281-291.

UNIONIDAE OF THE PAMUNKEY

RIVER SYSTEM, VIRGINIA
Fred B. Blood and Marceile B. Riddick

Biology Department

Virginia Commonwealth University

Richmond, Virginia 23220

During the Fall and Winter of 1972 and
Spring of 1973, the investigators collected
over 1200 unionid specimens on the Pamun-
key River System (York River Drainage). The
following is a listing of species collected:
Elliptio complanata (Lightfoot)
*E. angustata (Lea)
E. lanceolata (Lea)
*Lampsilis radiata radiata (Gmelin)
L. cariosa {Say)
*Ligumia nasuta (Say)
Alasmidonta undulata (Say)

*A. heterodon (Lea)
Lasmigonia subviridis (Conrad)
*Anodonta cataracta cataracta (Say)
Elliptio complanata comprised approxi-
mately 85% of the specimens. By the most
recent records available (Johnson, 1970), the
indicated species (*) are drainage records for
the river system. A specimen of Anodonta
implicata (Say), also a drainage record, was
collected on the James River below Rich-
mond, Va.

The authors are indebted to Dr. J. P. E.
Morrison for his assistance in identification.

LITERATURE CITED

Johnson, R. I. 1970. The Systematics and
Zoogeography of the Unionidae (Mollusca:
Bivalvia) of the Southern Atlantic Slope
Region Bull. Mus. Comp. Zool. 140:6.

66 THE NAUTILUS

April 30, 1974

Vol. 88 (2)

ARION SUBFUSCUS IN THE VICINITY OF WASHINGTON, D.C.

Lowell L. Getz

Provisional Department of Ecology, Ethology and Evolution,
University of Illinois, Urbana, Illinois, 61801

The previously recorded distribution of the
introduced European slug, Arion subfuscus
(Draparnaud, 1805), in eastern North
America extended on the west from Green-
wich, Connecticut, northward through the
Catskill and Adirondack mountains to the St.
Lawrence River and eastward to the coast
(and onto Newfoundland); there is also a
population recorded from the Kipawa Reserve
in Eastern Ontario. In addition, there are
scattered records from Pennsylvania and one
from East Aurora, New York (Chichester and
Getz, 1969; Getz and Chichester, 1970).

Spot checks made in the vicinity of
Washington, D.C. during July 1973, indicated
Arion subfuscus to be very abundant in this
region. Collections were made in Falls
Church, Virginia and Bethesda, Maryland. A.
subfuscus, along with another introduced
slug, Umax maximus, was found in high
densities in flower beds and lawns at both of
these sites. Discussions with individuals living
in various places within the District of
Columbia and surrounding communities indi-
cated both species to be common throughout
the metropolitan region. The only previous
record oi Arion from the District of Columbia
is A. fasciatus (Nilsson) (as circumscriptus
Johnston, by Pilsbry, 1948). The abundance
of A. subfuscus indicates the species has been
present in this region for a considerable
period of time, however.

Examination of the individuals from the
two populations revealed a much more
heterogeneous assemblage of color forms than
was observed in any of the local populations
in New England. Individuals resembling three
of the four color forms (Forms 1, 2, and 4;
Chichester and Getz, 1969) identified in New
England occurred at both sample sites; only
the unhanded, yellow-orange form (Form 3)

was not observed. In addition there was
greater intergradation between color forms
than was observed in most other local
populations. There was a continuous range of
color from an almost completely black
dorsum above the lateral bands (as in Form 1)
to a very light yellowish-brown form with
light lateral bands (Form 4). This intergrada-
tion of color forms indicates a possible long
existence of the species in the region.

The presence of such an abundant,
unreported population of A. subfuscus
existing in this region emphasizes an earlier
comment concerning the need for more
detailed information concerning distribution
of introduced European slugs (Chichester and
Getz, 1968).

ACKNOWLEDGEMENTS

I wish to thank Mrs. Margaret Gray Towne
for pointing out existence of the slugs in Falls
Church and Miss Barbara Buckingham for
assistance in obtaining the collection from
Bethesda.

LITERATURE CITED

Chichester, L. F. and L. L. Getz. 1969. The
zoogeography £md ecology of arionid and
limacid slugs introduced into Northeastern
North America. Malacologia 7: 313-346.

Chichester, L. F. and L. L. Getz. 1968.

Terrestrial Slugs. The Biologist 50:

148-166.
Getz, L. L. and L. F. Chichester. 1971.

Introduced Slugs. The Biologist 53:

118-127.
Pilsbry, H. A. 1948. Land Mollusca of North

America (North of Mexico). Monogr. 3,

Acad. Nat. Sci. Philadelphia 2 (2):

521-1113.

Vol. 88 (2)

THE NAUTILUS

GALAPAGOS BULIMULIDS:

A TAXONOMIC CORRECTION

Allyn G. Smith

Research Associate, Dept. of Geology

California Academy of Sciences

San Francisco, California 94118

Dr. Abraham S. H. Bruere, Division of
Systematic Zoology, University of Leiden,
Leiden, The Netherlands, who is studying the
Bulimulidae, has kindly and quite properly
called my attention to a taxonomic situation
that needs correction. Last year I described
three new land snails from Isla Santa Cruz
(Indefatigable Island), Galapagos, that were
presumed to be new species (Smith, 1972).
These were Naesiotus cavagnaroi, N. deroyi,
and N. scalesiana. At the time this report was
being prepared I was totally unaware of the
important contribution by the distinguished
Swedish malacologist. Dr. Nils H. Odhner, in
which two new Galapagos land snail species
were described, also from Isla Santa Cruz, as
Bulimulus blombergi and B. eos, respectively
(Odhner, 1951). Careful reading of Odhner's
descriptions along with a review of his
excellent illustrations leave no doubts that
Naesiotus deroyi A. G. Smith, 1972, is
exactly the same species as N. blombergi
(Odhner, 1951), and that N. scalesiana A. G.
Smith, 1972, is completely equivalent to N.
eos (Odhner, 1951). My new names, there-
fore, should be placed into the synonymies of
Odhner's species names. Apologies are in
order for the inadvertent creation of two
synonyms in the Mollusca: Stylommatophora,
family Bulimulidae, and for unnessarily
complicating the taxonomy of the
family-group to this extent.

LITERATURE CITED

Odhner, Nils Hjalmar. 1951. Studies on
Galapagos Bulimulids. Journal de Conch-
yliologie, 90(4):253-268, 2 pis. (figs. 1-13).
Paris. 25 January. [In English] .

Smith, Allyn Goodwin. 1972. Three new land
snails from Isla Santa Cruz (Indefatigable
Island), Galapagos. Proc. California Acad.
Sci., (4), 39(2): 7-24, figs. 1-25. San
Francisco. January 21.

ANOTHER FOSSIL OVO VIVIPAROUS
TURRITELLA

Joan Antill

4201 Cathedral Avenue, N. W.
Washington, D. C. 20016

At the Kenneth E. Rice Fossil Pit of
Miocene age at Hampton, Virginia, in
September 1973, the writer found a 37-mm
specimen of Turritella alticostata Conrad that
contained 41 preserved immature shells. This
is the fifth species of Turritella from the
Chesapeake and Floridian Miocene which is
known to have ovoviviparous reproduction.
The species was kindly identified by Druid
Wilson, Geologist of the U. S. Geological
Survey at the Smithsonian Institution. The
specimens are in the collection of the writer
at present, but vnll be given to the Kenneth E.
Rice Memorial Museum shortly.

Palmer, Katherine V. W. 1961. Additional
Note on Ovoviviparous Turritella Jour.
Paleont. 35(3): 633.

Sutton, A. H. 1935. Ovoviviparous Repro-
duction of Miocene Turritellidae. Amer.
Midland Nat. 16(1):107-109.

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THE

NAUTILUS

Volume 88, number 3 — July 1974

CONTENTS

Robert C. Bullock

A Contribution to the Systematics of Some West Indian

Latiruf: (Gastropoda: Fasciolariidae) 69

R. D. Turner and W. J. Clench

A New Blind Physa from Wyoming with Notes on its

Adaptation to the Cave Environment 80

Joseph Vagvolgyi

Nesupupa galapagensis, a New Indo-Pacific Element

in the Land Snail Fauna of the Galapagos Islands

(Pulmonata: Vertiginidae) 86

Samuel L. H. Fuller

Neglected Papers on Naiades by W. I. Utterback 90

Recent Publications 79

A.M.U. Notice 89

III

Vol. 88 (3)

THE NAUTILUS

A CONTRIBUTION TO THE SYSTEMATICS OF
SOME WEST INDIAN LATIRUS (GASTROPODA: FASCIOLARIIDAE)

Robert C. Bullock

Department of Biological Sciences

Florida Technological University

Orlando, Florida 32816

ABSTRACT

Some West Indian members of the taxonomically difficult genus Latirus are
considered. The two most common species, generally recognized as Latirus
brevicaudatus (Reeve, 18^7) and L. mcgintyi Pilsbry, 1939, are highly polymor-
phic and have been described in the literature under a number of names; due to
the present confusion s^irrminding these species, some nomendatorial changes
appear necessary, and they are herein called Latirus angulatus (R'dding. 1798)
and L. cariniferus (Lamarck, 1816), respectively. Latirus (Polygona) bernadensis
from Barbados is introduced as a new species; Latirus (Polygona) nematus
Woodring, 1928, originally described from the Bowden Formation, Jamaica, is
noted for the first time as a member of the Recent fauna.

INTRODUCTION

While studying the fasciolariid genus Latirus
in the western Atlantic, some conclusions have
been reached pertaining to the subgenera
Latirus s.s. and Polygona and these results are
presented in this paper. It is hoped that a
monograph covering all the West Indian species
of the genus will be completed in the near
future.

The genus Latirus includes a variety of
fasciolariid species characterized by being spin-
dle-shaped, generally rather heavy-shelled, and
with prominent folds on the columella. The
great diversity of form has encouraged some
authors to create generic and subgeneric names,
and some of these appear to be very useful in
an evolutionary treatment of the group.

Among the Peristemiinae, the group most
closely related to Latirus is also composed of
diverse members and is well represented in the
New World by the genus Leucozonia. The latter
group can be distinguished from Latirus by its
more open siphonal canal, which actually forms
the lower portion of the aperture; also, there is
an interesting difference in the radula, the
small node or cusp on the medial end of the
lateral tooth being greatly reduced or absent in
Leucozonia. Some, but not all, Leucozonia
possess a tooth on the outer lip at the base of

the aperture. For these reasons, the genus
Leucozonia [type species Leucozonia nassa
(Gmelin) from the West Indies] includes
Leucozonia ocellata (Gmelin), also Caribbean,
and Leucozonia cerata (Wood), L. rudis (Reeve),
and L. tuberculatus (Broderip) from the eastern
Pacific. While some of these generic com-
binations were noted by Keen (1971) in her
treatment of eastern Pacific MoUusca, rudis was
incorrectly considered to belong to Latirtis.

Other Peristemiinae similar to Latirus, but
apparently more closely related to Leucozonia,
include: the Indo-Pacific Latirolagena
smaragdula (Linnaeus) and the eastern Pacific
Opeatostoma pseudodon (Burrow) which have a
typical Leucozonia-tyw radula; and "Latirus"
amplustris (Martyn), from the Indo-Pacific. It
should be mentioned here that the generic dif-
ferences noted above indicate that the radula of
Latirus gibbulus (Gmelin), the type species of
the genus Latirus, will prove to be of the
Leucozonia-tyTpe. The heavy shell of Latirus gib-
bulus. its reduced spiral and axial sculpture,
and its open siphonal canal indicate a likely
Leucozonia affinity. Should the radula of L.
gibbulus be found to be that of a Leucozonia, it
would certainly pose an interesting problem
concerning the correct generic names for the
species presently considered to be Latirus and
Leucozonia. The functional significance of the

70 THE NAUTILUS

July 22, 1974

Vol. 88 (3)

Explanation to Latinis figures 1-11 on opposite page

Vol. 88 (3)

THE NAUTILUS

reduced medial node of the lateral tooth of the
Leucozonia-type radula is not known, and its
use as a phylogenetic character is slightly
questionable due to the limited amount of
material available for study.

Genus Latinis Montfort, 1810

Latinis Montfort, 1810, Conchy liologie systema-
tique et classification methodique des co-
quilles 2: 531. Type species, Latirus auranti-
acus Montfort, 1810, by monotypy [ =L.
gibbulus (Gmelin, 1791)].

Chascax R. Watson, 1873, Proc. Zool. Soc.
London for 1873: 361. Type species, Chascax
maderensis Watson, 1873, by monotypy
[ = Latirus armatiis A. Adams, 1855] ; non
Chascax Ritgen, 1828 (Reptilia).

Hemipolygona Rovereto, 1899, Atti Soc. Ligust.
10:104 (new name for C/ioscox Watson, 1873).

[?] Ruscida Casey, 1904, Trans. Acad. Sci. St.
Louis 14: 161. Type species, designated by
Palmer (1937), Fusus plicata Lea.

Subgenus Latirus s.s.

Latirus (Latinis) carinifenis (Lamarck, 1816)
Figs. 2-6, 9, 11, 18, 22

1816 Fusns carinifenis Lamarck, Eiicyclopedique
methodique, pi. 423, fig. 3. Name and figure
only; locality unknown. Type locality herein

designated to be Cienfuegos, Cuba. Type not
in Musee d'Histoire naturelle, Geneva.

1855 Latirus distinctvs A. Adams, Proc. Zool.
Soc. London for 1854: 314. Locality unknown;
type locality herein designated to be off
Washerwomans Shoals, Key West, Florida.
Lectotype, herein selected, BMNH 196738/1
(see Fig. 2).

1874 Plicatella trochleari^ Kobelt, [in] Martini-
Chemnitz, Syst. Conch.-Cab. 3 (3A): 79, pi.
19, figs. 1, 2. Type locality: St. Jan [= St.
Johns, Virgin Islands]. Location of type
unknowm.

1939 Latinis mcgintyi Pilsbry, Nautilus 52: 84,
pi. 5, fig. 8. Type locality: Lake Worth,
Palm Beach Co., Florida. Holotype ANSP
173960.

Description: Shell highly variable, heavy, up
to 73 mm in length and 36.8 mm in greatest
diameter. Whorls 8-9, including IV2 whorls of
the protoconch. Spire about half the length of
the shell, but sometimes slightly less. Aperture
almost square and twice as long as the short,
thick siphonal canal. Axial sculpture of 8-9
moderately pronounced, squarish ribs. Spiral
sculpture of heavy cords which begin at the
shoulder of the whorl and continue anteriorly
to the tip of the siphonal canal. 2-3 cords
visible on the upper whorls, 5 on the body
whorl, the 2 lowest closer together and being
characteristic of this species. Between spiral
cords 6-7 fine threads usually present but may

FIG. 1. Latirus nematus Woodring, Holotype.

USNM 369U2. Miocene of Bowden, Jamaica.

L6X.

FIG. 2. Latirus cariniferus (Lamarck), Lectotype

of Latirus distinctus A. Adams, BMNH

196738/1. 1.7X. Photograph courtesy of the

British Museum (Natural History).

FIG. 3. Latirus cariniferus (Lamarck), Steger

collection no. U16. Matanzas, Cuba. 1.3X.

FIG. k. Latirus cariniferus (Lamarck), USNM

36Jf362. Vicinity of Cartagena, Colombia. 1..5X.

FIG. 5. Latirus cariniferus (Lamarck), Tyj^e

figure of Fusus cariniferus Lamarck, Encycl.

Meth. pi. m, fw- 3. I.IX.

FIG. 6. Latirus cariniferus (Lamarck), USNM

,589534. Colon, Panama. 1.5X.
FIG. 7. Latirus angulatus (Rodirig), Type figure
of Fusus angulatus Roding, Syst. Conch.-Cab. 4,
fig. 1315. 1.2 X.

FIG. 8. Latirus angulatus (Roding), specimen in
MCZ. Just E. of Piscadera baai, Curacao.
Netherlands Antilles. l.SX.
FIG. 9. Latirus cariniferus (Lamarck), AMNH
100.575. W. of Cedar Key, Florida, 20fms. 1.2 X.
FIG. la Latirus angulatus (Roding), AMNH
125i89. Curacao, Netherlands Antilles, 6 fms. 1.1
X. *

FIG. 11. Latirus cariniferus (Lamarck), MCZ
23Wh. Cienfuegos, Cuba. 1.3X.

72 THE NAUTILUS

Julv 22. 1974

Vol. 88 (3)

be entirely absent. Sutural ramp devoid of
major cords, although possibly with numerous
spiral threads; at times this area is completely
smooth. Columella with 2 folds with a weaker
one below; occasionally 4 strong folds. Outer lip
crenulated due to spiral sculpture. Within the
lip are 13-22 irregular lirae which may be very
weak. Fasciole present, sometimes very
pronounced. Anal canal partially developed.

Color white, yellow, or light cream-orange.
Spiral cords usually the same color as shell, but
at times white. Many specimens, but not all,
with a reddish brown bar between each axial
rib of the earlier whorls. Some specimens have
brown between the white spiral cords.
Periostracum thin and light brown.

Remarks: This is a highly variable species,
but the two conspicuous, heavy, contiguous
spiral cords at the base of the body whorl serve
to distinguish it from all other Latinis. This
characteristic is observed in Lamarck's figure of
Fusus cariniferns (Fig. 5), a name which has
been overlooked by recent authors and misun-
derstood by earlier ones such as Paetel (1873,
1888), Tryon (1881), and Melvill (1891).

Deshayes & Milne Edwards (1843) mentioned
that Lamarck had confused Turbinella spinosa
Martyn with this species; they restricted the
name carinifems to the species figured by
Lamarck in the Eiicyclopedique Methodique.

The well-known names mcgintyi Pilsbry,
trochlem-hi Kobelt, and distinctus A. Adams are
all herein synonymized with cariniferus since
they represent only a few of the many
variations exhibited by this species. The shell of

cariniferus is somewhat similar to Latinis ar-
matus A. Adams of the eastern Atlantic and an
un-named species from Somalia; both, however,
lack the two prominent contiguous spiral cords
at the base of the body whorl. Only two
western Atlantic specimens have been observed
which lack the contiguous cords (ANSP 314265,
La Gonave Id., Haiti). Tryon (1881) erroneously
mentioned Chascax maderensis Watson [ =
Lafinis amiatus A. Adams] as a West Indian
species.

Radular studies reveal that L. cariniferus is
probably more closely related to L. tumens Car-
penter from the Panamic Province than to ar-
matus. The only other member of Latirus s.s.
from the Caribbean is L. varai Bullock, 1970,
which may easily be differentiated by its
stronger spiral sculpture, more rounded whorls,
and chestnut brown coloration on the axial ribs,
not between them.

The fossil record of canm/en^-like Latirus is
incomplete and known mostly from the
Pliocene. Pilsbry (1939) described L. maxivelli
which differs from carinifems by having
stronger spiral cords and less pronounced axial
ribs. Latirus ana-petes Woodring, 1964, from the
Chagres Sandstone (Pliocene) of Panama is also
an early representative of cariniferus. differing
by being more attenuate and having strong
spiral cords. Woodring compared anapetes with
a very closely related species, taurus Olsson,
1922, from the Gatun Formation of the Toro
cays.

Distribution: From Palm Beach and the west
coast of Florida in the north, this species ex-

FIGS. 12. 19. Latirus nematus Woodring. USNM

JfU9.Jl. Bear Cut, Miami. Florida, 25 fms. 12.

2.2.X; 19. 1.9X.

FIG. VJ. Latirus (Polygona) bernadensis Bullock.

n. sp., Holotype. MCZ 275.i28. Barbados Island,

Lesser Antilles. 2X.

FKi. 14. Latirus infundibulum (Gmelin). Finlay

collection. Ayuadilla, Puerto Rico. 1.2X.

FIG. 15. Latirus infundibulum (Ctmelin), AMNH

11520:1 Frmn fish traps in 10 fms.. Guantanamo

Bay, Cuba. 1.3X.

FIG. 16. Latirus angulatus (Rodim)). USNM

6f!:mo. Water Id.. Vi)yin Islands. 22X.

FIG. 17. Latirus angulatus (Rddim/), USNM

4U897. Cardenas Bay. Cuba. 1-3 fms. 2lX.

FIG. 18. Latirus cariniferus (Lamarck). Finlay

collection. Off Gibara, Oriente. Cuba, KH) fm,^.

l.:3X.

FIG. 20 Latirus angulatus (Roding). AMNH

U0U8. Off Forialeza, Ce.arci. Brazil, 12 fms.

2.2X.

FIG. 21. Latirus angulatus (Roding). specimen

in MCZ. N coast of South Ameriea, dredged.

2.3X.

FIG. 22. Latirus cariniferus (Lamarck). DAt-

tillio collection no. 13^. Cienfuegos Harbor,

Cuba. 0.8X.

Vol. 88 (3)

THE NAUTILUS

Explanation to Latmis figures 12-22 on opposite page

74 THE NAUTILUS

July 22, lWi4

Vol. 88 (3)

tends throughout the West Indies, and from
Yucatan, Mexico, to the northern coast of South
America, from shallow water to over 100
fathoms.

Subgenus Polygona Schumacher, 1817

Polyyana Schumacher, 1817, Essai d'un nouveau
sys£eme des habitations des vers testaces, pp.
73, 241. Type species, Polygona fusifornm
Schumacher, 1817, by monotypy [ = Latirus
infundibulum (Gmelin, 1791)].

Plicatella Swainson, 1840, Treatise on mal-
acology, pp. 78, 304. An unnecessary new
name for Polygona Schumacher.

Remarks: As Woodring (1928) mentioned,
Latirus infundibulum (Figs. 14, 15) is e.xtremely
different from L. 'gibbubu^ the type species of
Latiiiis. But Woodring admitted that in terms
of shell morphology there exist species in-
termediate between Latirus s.s. and Polygona.
The latter differs from Latirus by being
smaller, relatively more narrow, having a well
developed siphonal canal, and usually with
pronounced brown, rather than white, spiral
cords. It seems wise at this time to retain the
use of Polygona at the subgeneric level only.

Species referable to Polygona appear com-
monly in the Miocene of the Caribbean region.
This group, as with other Latim.% includes
some species having a high degree of in-
traspecific variation of shell characters. Recent
West Indian species of Polygona include in-
fundibulum (Gmelin), angulatus (Roding),
nematus Woodring, and bernadensis Bullock, n.
sp.; hemphilli Hertlein & Strong, corwentricus
(Reeve), and praestantior Melvill are eastern
Pacific representatives.

Latirus (Polygomi) angulatus (Roding, 1798)
Figs. 7, 8, 10, 16, 17, 20, 21, 24-26

1798 Fusus angulatus Roding, Museum Bolten-
ianum, p. 118, sp. 1527. Locality not men-
tioned; type locality herein designated to be
San Juan baai, Curacao, Netherlands Antilles.
Location of type unknown.

1847 Turbinella bremcaudata Reeve, Conchologia
Iconica 4, Turbinella pi. 10, sp. 50. Locality

unknown: figured specimen in BMNH. A
doubtful synonym of Latirus angulatus.

1847 Turbinella spadicea Reeve, Conchologia
Iconica 4, Turbinella pi. 9, sp. 44. Locality
unknown. Possible syntypes in BMNH.

1940 Latirus cymatius Schwengel, Nautilus 53:
110, pi. 12, figs. 6, 7. Type locality: off Palm
Beach, in about 12 fms. Holotype ANSP
175132. Misspelled cymatias on p. 110, but
correctly on plate caption.

Description: Shell small to large, up to 76.5
mm in length and 34 mm in greatest diameter.
Spire usually more than half the length of the
shell, but sometimes less. Whorls 9-10; protoconch-
consisting of 2 whorls. Aperture oval to
squarish and greater in length than the short
siphonal canal. Axial sculpture of 7-8 squarish
ribs which often are more pronounced just below
the shoulder of the whorl. Numerous fine
growth lines usually very conspicuous at the
suture. Spiral sculpture of 8-10 heavy cords, 4-5
showing on the upper whorls, interspaced with
secondary, and sometimes tertiary, threads.
Columella with 3 folds and a weaker one below.
Outer lip crenulated, the indentations
corresponding to the spiral sculpture. Within
the lip 7-12 lirae run into the aperture.
Fasciole present. Anal canal partially developed.

Color light cream-orange to brown. Spiral
cords and threads reddish brown or at times
the color of the shell. Shell occasionally banded
with light reddish brown. Periostracum very
thin, light brown.

Kemarks: Much taxonomic confusion has
existed concerning Latirus angulatus. An in-
dication of the problems associated with this
species first came when T. L. McGinty (1966, in
litt. to Dr. R. D. Turner of Harvard Univer-
sity), who had been working on Latirus. stated
that the well known name brevicaudatus could
refer to a Pacific species. A study of many
hundreds of West Indian specimens has resulted
in the conclusion that this relatively common
species exhibits more intraspecific variation
than any other Latirus I have observed, and
not one of the many forms can be rampared
easily with the clear figure in Reeve (1847) or
a photograph of the specimen provided me (Fig.
23) by Dr. Norman Tebble, the former curator

Vol. 88 (3)

THE NAUTILUS

of the MoUusca section of the British Museum
(Natural History). When I had the opportunity
to examine the figured specimen first hand, I
found the Reeve figure to be an exceptionally
gO(xl one. An additional complication developed
when it became apparent that the figured type
of hrepicandatus seemed to have much in com-
mon with a few Indo-Pacific specimens labelled
"La^^^/,s• li/ratus Rve." in some museum collec-
tions. The problem remained: what should be
done in this particular case, especially since the
name breincmidatus was prevalent, in spite of
the other names applied to this species?

The "type lot" of hrevicaudahis includes ttiree
specimens. In addition to the previously men-
tioned figured type, there are two specimens
(Figs. 24, 26) that are clearly referable to the
Virgin Island form of "brevicaudatus" (Fig. 16).
These two specimens are so very different from
the figured specimen that I find it hard to
believe that Reeve had access to them when he
was completing the Turhinella section of the
Conchologia Iconica. I feel it is likely that these
two specimens were added to the type lot at a
later date.

There are four possible courses of action one
could take in this particular case: 1) conserve
the name hrevicaiidatus for the West Indian
species by continuing to accept the figured type
as the Caribbean species, 2) conserve the name
bremcaudatm by ignoring the figured type and
declaring one of the other specimens to be the
lectotype, 3) avoid the entire problem by using
an earlier name, 4) petition the Comission on
International Zoological Nomenclature to in-
validate the existing types and establish a
neotype based on a typical example of
brevicaudatus. But to conserve the name
brevicaudatus for the Caribbean species would
make it unavailable for future use should it be
found that brevicaudatus actually occurs in the
Indo-Pacific, which seems likely, or in the
eastern Atlantic, where it has been reported
by Nordsieck (1968).

If one is willing to accept a change of name
for this West Indian species, the easiest choice
is to use the next available name. But both
names from the literature that could be used
for this species, spadkeus (Reeve, 1847) and
cymatius Schwengel, 1940, do not represent

typical forms, and since the great intraspecific
variation observed is still not clearly un-
derstood, the use of these names might institute
confusion. A better solution does exist, however.
In the Museum Boltenianum, using the name
Fusus angulatus, Roding (1798) made reference
to a certain specimen figured by Chemnitz (my
Fig. 7) in the Systematisches Conchylien-Cabinet
(vol. 4, figs. 1314, 1315). These two figures,
which have been cited repetitiously by earlier
authors as two of a number of figures of
Latirus polygonus (Gmelin, 1791), are
definitely not conspecific with Gmelin's abun-
dant and well understood Indo-Pacific species;
they represent a large "breincaudatus" nearly
identical to a typical form occurring in the
southern Caribbean (compare Figs. 7, 8, and 10).
The mention by Chemnitz of brown spiral
threads is especially convincing.

Because of the uncertainty regarding the use
of the name brevicaudatus for the Caribbean
species, and because some typical West Indian
forms closely match the Chemnitz figure, I have
decided, with more than a little reluctance, to

FIG. 23. Latirus brevicaudatus (Reeve), Figured
type. Locality unknown. IX. Photograph cour-
tesy of the British Museum (Natural History).
FIGS. 2Jt, 26. Latirus angulatus (Roding).
"paratypes" of Turbinella brevicaudata Reeve.
Locality unknoum. IX. Photographs courtesy of
the British Museum (Natural Histmij).
FIG. 2.5. Latirus angulatus (Roding), possible
syntype of Turbinella spadicea Reeve, fide Dr.
Norman Tebble. Locality unknown. iX.
Photograph courtesy of the British Museum
(Natural History).

76 THE NAUTILUS

July 22, 1974

Vol. 88 (3)

propose the use of the name angulatus (Roding,
1798) for this species. It is felt that the
establishment of the name nugiilatm will prove
not only to have been an expedient move, but
one that will have promoted nomenclatorial
stability, one of the ultimate goals of most
taxonomists.

As previously mentioned, LatmiH angulatius
exhibits a great amount of intraspecific
variation. Typical anyulatus. similar to the
"paratypes" of hremcauckitus, occur on St.
Thomas and St. Johns, Virgin Islands (Fig. 16),
and in the Bahama Islands. The Lesser Antilles
afford the largest angulatus known, those from
Curacao (Figs. 8, 10) being especially large and
identical to the figure in Chemnitz (my Fig. 7);
these differ from the tjT)ical form only in the
adult, which has somewhat more swollen whorls
and slightly more squarish axial ribs. The
frilled sutural region of Curatjao specimens
(mentioned by Benthem Jutting, 1920) and those
from off Florida (Schwengel, 1940) is charac-
teristic of most angulatus. as well as many
other Latirns. and its expression is probably
dependent upon environmental conditions.

Major variations of angulatus occur
throughout the rest of its range. Several
specimens from South America show very
heavy spiral sculpture and a relatively small
aperture (Figs. 20, 21). L. ci/watius Schwengel
from Florida is closer to typical angulatus than
many of the other variations, and it is herein
considered conspecific with angulatus. The type
specimens of cymatius are unicolored Sayal
brown and heavy-shelled; most specimens
examined were immature. Numerous forms of
angulatus occur along the northern coast of
Cuba (one such form. Fig. 17).

The identity of Latinis spadieeus (Reeve,
1847) (Fig. 25) remains a little uncertain,
although I feel certain that some specimens of
Latims angulatus will eventually be collected
that will show Kpadiccus to be conspecific with
angulatus. Hertlein & Strong (1951) and Keen
(1971) stated that the west American Latirus
hcmpfulli Hertlein & Strong, 1951, wa.s the
spadiceus of authors, but not of Reeve. Some
older museum collections have some angulatus
specimens from unknown locality which seem
referable to spadiceus Reeve.

Some Miocene and Pliocene Latirus appear to
be possible ancestors of angulatus. The closest
relative, L. angulatus santodnmingeiisis Pilsbry
from the Miocene of the Dominican Republic,
differs from typical angulatus by having a shor-
ter, wider siphonal canal and a sharp
angulation of the axial ribs. Pilsbry 's descrip-
tion fits some Recent angulatus, and a few
specimens (fossil?) dredged from the harbor at
Roosevelt Roads Naval Base, Puerto Rico, ap-
pear to be intermediate between these two sub-
species.

Distribution: From the lower east coast of
Florida and the Bahama Islands in the north,
this species is found throughout the West In-
dian Province, from Yucatan, Mexico, and Cuba
to the Lesser Antilles and Brazil. Peile (1927)
recorded a "Latirus sp. near sanguifluus. Rve."
from Bermuda, but I have been unable to locate
his specimen. Recently, Waller (1973) collected
Latirus angulatus off the south shore of
Tucker's Town, Bennuda, 51 meters depth. Nord-
sieck (1968) reported this species from the
west coast of Africa, but the present author has
seen no eastern Atlantic specimens and cannot
verify this record.

Latirt(.'< (Poh/gona) hernadensis Bullock,

new species

Fig. 13

Description: Shell small to medium in size,
up to 44.2 mm in length and 16.5 mm in
greatest diameter. Spire slightly greater than
half the length of the shell. Aperture oval to
squarish and as long or slightly longer than the
moderately long siphonal canal. Whorls 9. Axial
sculpture of 7 broad ribs which are slightly
more pronounced on the shoulder of the whorl.
Spiral sculpture of about 8 cords with oc-
casional secondary cords between; 4-5 cords
show on the upper whorls, and a number of
cords, some stronger than others, are prominent
on the siphonal canal. Columella with 3 folds
with a weaker fold above and below these.
Outer lip crenulate due to the spiral sculpture;
within the lip 6-9 lirae run into the aperture.
Periostracum thin, light brown. Shell light
cream-orange, including the spiral cords. Aper-
ture slightly lighter in color.

Vol. 88 (3)

THE NAUTILUS

MrnsiDvmpnts: Holotype 44.2 mm in length,
1().5 mm in greatest diameter; paratypes (both
from the type locality) 36.7 and 36.4 mm in
length.

Tifpe locality: Barbados, Lesser Antilles.

Location of Types: Holotype, Museum of
Comparative Zoology, Harvard University,
275428; two paratypes, Mus. Comp. Zool. 275429.

Remarks: When compared with other West
Indian Latirus, bernadensis appears most
similar to L. infundihidum (Gmelin, 1791), but
differs by being relatively stouter, having
broader axial ribs, and lacking the brown
coloration on the stronger spiral cords. L.
praestantior Melvill, 1892, from West Me.xico is
closely related, but its spiral sculpture is not as
strong, especially on the body whorl. This
species is named after Bemados Island, a name
for Barbados appearing on an early sixteenth
century manuscript chart located in the British
Museum.

Latirus (Polygona) nematus Woodring, 1928
Figs. 1, 12, 19

1928 Latirus (Polygona)- nematus Woodring,
Miocene mollusks from Bowden, Jamaica.
Part II, Gastropods and discussion of results,
p. 254, pi. 15, fig. 6. Type locality: Bowden
Formation [Miocene], Jamaica. Holotype
USNM 369442.

Description: Shell moderately large, up to
60.4 mm in length, 23 mm in diameter. Spire
usually about half the length of the shell, but
sometimes less. Whorls 10, including Wz whorls
of the protoconch, which is often broken off or
eroded. Aperture oval and larger than the
rather short siphonal canal. Axial sculpture of
8-11 ribs. Numerous fine growth lines are
present. Spiral sculpture of many cords, usually
of even thickness, but occasionally showing
some secondary cords. In the region below the
shoulder and on the body whorl of some
specimens, the crossing of the growth lines and
the spiral cords gives the shell a cancellate ap-
pearance. Columellar folds 4, with the lower 2
partially fused. Outer lip minutely crenulate
with the formation of small teeth arranged in
pairs. Within the lip 10-14 irregular lirae run
into the aperture, the anterior one thickened

and corresponding to the most anterior
columellar fold and appearing to almost close
the apertural entrance to the siphonal canal.
Fasciole well developed; pseudoumbilicus slit-
like. Anal canal well defined.

Shell light cream-orange to almost white
with light orange on the siphonal canal, and oc-
casionally partially banded with reddish brown.
Early whorls Sayal brown. Aperture yellowish
white; columella light orange. Periostracum thin
and light greenish brown.

Remarks: Latinis nematus previously was
known only from the Bowden Formation, and
this marks the first time it has been reported
from the Recent fauna. The Recent specimens I
examined do differ in some respects from the
fossil form, particularly when immature
specimens are compared, and I at first thought
that perhaps they were specifically or sub-
specifically distinct. Most Recent specimens are
immature and exhibit quite inflated whorls; the
immature paratypes of nematus do not have in-
flated whorls, and are more elongate. It seems
best in this case to delay introduction of an ad-
ditional name until more material, both fossil
and Recent, is available for study.

When compared with other species, nematus
can possibly only be confused with some forms
of angulatus. The latter species usually can be
differentiated easily by its stronger spiral cords,
often with intermediate secondary cords which
are usually brown in color. In addition, the
axial ribs tend to be somewhat round. In
nematus. the spiral cords are fine and more
numerous, lack color, and the axial ribs are
more squarish in outline.

Distribution: Known only in the Recent
fauna from off Miami, Florida, and Gibara,
Oriente, Cuba. Usticke (pers. comm.) has a
specimen from the north coast of Puerto Rico
which is probably this species.

Specimens Examined: FLORIDA: Miami;
Miami, 20 fms.; Bear Cut, Miami, 25 fms. (all
USNM). CUBA: off Gibara, Oriente (Finlay
collection).

ACKNOWLEDGEMENTS

This paper is a revised version of a portion
of my dissertation of western Atlantic Latmts.
which was done under the direction of Dr. John

78 THE NAUTILUS

July 22, 1974

Vol. 88 (3)

H. Dearborn and presented to the Zoology
Department of the University of Maine at
Orono, for partial fulfillment of the requirements
of the Master of Sc-ience degree.

The loan of specimens and assistance during
my visits to their institutions were provided
by: W. J. Clench, R. D. Turner, and K. J. Boss,
Museum of Comparative Zoolog>', Harvard
University; J. Rosewater, C. Roper, and J.
Morrison. United States National Museum of
Natural History; W. K. Emerson and W. Old,
American Museum of Natural History; R. T.
Abbott and R. Robertson, Academy of Natural
Sciences of Philadelphia; J. Taylor and J.
Peake, British Museum (Natural History).
Thanks are also due the private collectors who
generously loaned or gave specimens from their
own collections: Mr. John Finlay, Mr. & Mrs.
Dan Steger, and Mr. Nowell-Usticke.

Financial aid for this study was provided, in
part, by: the University of Maine; the Biology
Department, Harvard University; National
Science Foundation grant GB27911, Dr. Reed
Rollins, principal investigator; and a Sigma Xi
Grant-in-Aid-of- Research.

Early drafts of this paper were reviewed by
Drs. J. H. Dearborn, K. J. Boss, and R. D. Tur-
ner. All conclusions are the responsibility of the
author.

LITERATURE CITED

Adams, A. 1855. Descriptions of twenty-seven

new species of shells from the collection of

Hugh Cuming, Esq. Proc. Zool. Soc. London

for 18.54: .311-317.
Benthem Jutting, T. van. 1920. Marine molluscs

of the island of Curacao. Bijdragen Dierkunde

25: 1-36.
Bullock, R. C. 1970. LatiniR varai a new fas-

ciolariid gastropod from the Caribbean. The

Nautilus 83: 133-135, 1 fig.
Casey, L. 1904. Notes on the Pleurotomidae

with descriptions of some new genera and

species. Trans. Acad. Sci. St. Louis 14:

123-170.
Chemnitz, J. 1780. Neues Systematisches

Conchylien-Cabinet 4. Niimberg, 344 pp.,

39 pis.

Deshayes, G. P., & H. Milne Edwards. 1843.
[in] J. Lamarck, Histoire naturelle des
animaux sans vertebres, 2nd ed., 9. Paris,
728 pp.

Hertlein, L. G., & A. M. Strong. 1951. Eastern
Pacific expeditions of the New York Zoo-
logical Society. XLIII. Mollusks from the west
coast of Mexico and Central America. Part X.
Zoologica 36: 67-120, pis. 1-10.

Keen, A. M. 1971. Sea Shells of tropical west
America, 2nd ed. Stanford, 1064 pp., illustr.

Kobelt, W. 1874. [in] Martini-Chemnitz, System-
atisches Conchylien-Cabinet 3 (3A), Turbinella
and Fasciolaria. Niimberg. 164 pp., .35 pis.

Kobelt, W. 1876. Catalog der Gattung Turbinella
Lam. Jahrb. Deutsch. Malak. (iesell. for 1876:
10-29.

Lamarck, J. 1816. Tableau encyclopedique et
methodique des trois regnes de la nature.
Paris, pis. .391-488.

Melvill, J. C. 1891. An historical account of the
genus Latinis (Montfort) and its depen-
dencies, with descriptions of eleven new
species, and a catalogue of Latirus and
Peristernia. Mem. Proc. Manchester Lit. Phil.
Soc. (4)4: 365-411,1 pi.

Melvill, J. C. 1892. Description of a new species of
Lntmi.H. Mem. Proc. Manchester Lit. Phil. Soc.
(4) 5: 92-93.

Montfort, P. D. de. 1810. Conchyliologie syste-
matique et classification methodique des
coquilles ... 2. Paris, 676 pp.

Nordsieck, F. 1968. Die europ'aischen Meeres-
Geh'auseschnecken (Prosobranchia). Stuttgart,
273 pp., 35 pis.

Olsson, A. A. 1922. The Miocene of northern
Costa Rica. Bull. Amer. Paleont. 9 (39):
309 pp., 32 pis.

Paetel, F. 1873. Catalog der Conchylien-
Sammlung. Berlin, 172 pp.

Paetel, F. 1888. Catalog der Conchy lien-
Sammlung 1. Berlin, 639 pp.

Palmer, K. 1937. The Claibomian Scaphopoda.
Gastropoda and dibranchiate Cephalopoda of
the southern United States. Bull. .-^mer.
Paleont. 7 (32): 370 pp., 90 pis.

Peile, A. 1926. The Mollusca of Bermuda. Proc.

Malac. Soc. London 17: 71-98.
Pilsbiy, H. A. 1922. Revision of W. M. Gabbs
Tertiary Mollusca of Santo Domingo. Proc.

Vol. 88 (3)

THENALTTILUS

Acad. Nat. Sci. Philadelphia 73: 305-435.
Pilsbry, H. A. 1939. A triad of umbilicate

Latirus, Recent and Pliocene. The Nautilus

52: 84-86, 1 pi.
Reeve, L. 1847. Conchologia Iconica 4:

Tiirbinella. pis. 1-13.
Roding. P. 1798. Museum Boltenianum.

Hamburg, 199 pp.
Rovereto, 1899. Atti Soc. Ligust. 10: 104

[publication not seen].
Schumacher, C. F. 1817. Essais d'un nouveau

systeme des habitations des vers testaces.

Copenhagen, 287 pp., 22 pis.
Schwengel, J. S. 1940. TVo new Floridan shells.

The Nautilus 53: 109-110, pi. 12 (in part).
Swainson, W. 1840. A treatise on malacology or

shells and shell fish. Cabinet Cyclopedia of

Natural History. London, 419 pp.
Tryon, G. W. 1881. Manual of Conchology 3.

Philadelphia, 310 pp., 87 pis.

Waller, T R. 1973. The habits and habitats of
some Bermudian marine mollusks. Nautilus
87: 31-52.

Watson, R. 1873. On some marine Mollusca
from Madeira, including a new genus of the
Muricidae, a new Eulima, and the whole of
the Rissoae of the group of islands. Proc.
Zool. Soc. London for 1873: 361-393, 2 pis.

Woodring, W. 1928. Miocene mollusks from
Bowden, Jamaica. Part IL Gastropods and
discussion of results. Carnegie Inst. Washing-
ton Publ. No. 385, 564 pp., 40 pis.

Woodring, W. 1964. Geology and paleontology of
the Canal Zone and adjoining parts of
Panama. Description of Tertiary mollusks
(gastropods: Columbellidae to Volutidae).
U. S. Geol. Survey Prof. Paper 306-C: 241-
297, pis. 39-47.

RECENT PUBLICATIONS

Shoup, Charles S. 1974. A Bibliography of the
Zoology of Tennessee and the Tennessee
Valley Region. Publ. NP-19905, National
Information Center, U. S. Dept. Commerce,
Springfield, Va. 22151, $7.50. 255 pp., 3350
entries by subject and localities. About 360
mollusk papers listed. Excellent.

(kistropodia, vol. 1, no. 9, Jan. 1974, pp. 85-96.
Glenn R. Webb, editor. Route 1, Box 148,
Fleetwood, Pa. 19522.

Goodhue, William Walter. 1974. The External
and Internal Morphology of the Common
Atlantic Squid, Loligo pealii Lesueur.
Vantage Press, N. Y., 74 pp., 25 photos, hard-
back, $5.00.

Jacobson, Morris K. and K. J. Boss. 1973. The
Jamaican Land Shells Described by C. B.
Adams. Occasional Papers on Mollusks
(Harvard), vol. 3, no. 47, pp. 305-520. The
types of 360 species are discussed, their
original descriptions reprinted, and most of
them illustrated. $5.50 to individuals.

Johnson, Richard I. 1973. Heude's Molluscan
Types, or Asian Land and Fresh Water
Mollusks, Mostly from the People's Republic
of China, Described by P. M. Heude. Special
Occasional Publication, no. 1, 111 pp.
(planographed, softbound). $2.50.

Smith. Shelagh M. 1974. Key to the British

Marine Gastropoda. Natural History Informa-
tion Series no. 1, 44 pp., 4 figs. Royal
Scottish Museum, Chambers Street, Edinburgh
EHl IJF, Scotland. Difficult to use and re-
quires consulting expensive library for
illustrations.

Pace, Gary L. 1973. The Freshwater Snails of
Taiwan (Formosa). Supplement 1, Malacologi-
cal Review. 118 pp., 18 pis., 17 text figs. A
much-needed and well-done treatment with
excellent illustrations. A useful handbook for
parasitologists and malacologists.

Okutani, Takashi. 1973. Guide and Keys to
Squid in Japan. Bull. Tokai Regional Fish.
Research Lab., no. 74, pp. 83-111. 86
drawings.

Okutani, Takashi. 1972. Molluscan Fauna on the
Submarine Banks Zenisu, Hyotanse, and
Takase, near the Izu-Shichito Islands. Ibid..
no. 72, pp. 63-142, 2 color pis. 5 new species,
including Profundiconus scofndicola.

Leme, Jose Luiz Moreira. 1973. Anatomy and
Systematics of the Neotropical Strophochei-
loidea (Gastropoda, Pulmonata) With the
Description of a New Family. Arquivos de
Zoologia, vol. 23, pt. 5, pp. 295-336, 54 illus.
Megalobulimidae, a new family is separated
off from Strophocheilidae (sensu Bequaert,
1948).

80 THE NAUTILUS

July 22, 1974

Vol. 88 (3)

A NEW BLIND PHYSA FROM WYOMING WITH NOTES
ON ITS ADAPTATION TO THE CAVE ENVIRONMENT

R. D. Turner and W. J. Clench

Museum of Comparative Zoology

Harvard University

Cambridge, Mass. 02138

ABSTRACT

Physa spelunca, netv species, is described. The ecology of the cave and adap-
tationt^ of the Physa to the cave environment are disciissed.

While looking for crustaceans, particularly
amphipods of the genus Stygobromus. in Low^er
Kane Cave, Wyoming, Dr. John R. Holsinger
collected a number of blind Physa which he
sent to us for identification. There were no
Stygobromus in the cave and, in fact, other
than the snails, all he found were a few
clusters of oligochaetes, probably tubificids. He
did not find anything in the spring outside the
cave.

In his letter to us about the cave Dr.
Holsinger wrote:

"Lower Kane Cave is a solution cave developed in
Paleozoic limestone. It's entrance is situated just
above and east of the Big Horn River, about 12
miles east of Lovell and at an altitude of 3,000 feet.
A stream flows through the cave and passes to the
surface through a spring just below the entrance.
The water from this spring flows directly into the
Big Horn River. The .source of the cave stream is a
'hot spring' at the far end of the cave, some 1,000
feet from the entrance. The stream temperature was
70° to 72° F [21-22° C] and that of the air in the
cave was 78° to 80° F. The water was hard and
had a strong sulphurous odor "

According to Dr. Holsinger, warm or hot cave
streams are extremely rare. In fact the only
other such cave with which he is acquainted is
Warm River Cave in Allegheny County,
Virginia. Brues (1932: p. 274-277)" listed 19
species of gastropods occuring in hot springs
and stated that "Physa seems to be the
dominate type in thermal waters." In addition
to thermal tolerance, species in this genus can
tolerate brackish water, and they are usually
the last of the snails to succumb when a
stream becomes heavily polluted. Thus it is not
surprising that Physa was the only snail found

in Lower Kane Cave, particularly as the works
of Henderson (1924, 1936) indicate that
hydrobiids, species of which commonly occur in
caves, are rare in this area. He did not list any
hydrobiids in his Wyoming paper (1918) nor did
Beetle (1961) report any from streams in the
Big Horn Mountains.

In Lower Kane Cave the Physa were common
on the surface of small rocks submerged in
rather fast -moving water well-back in the dark
zone of the cave, some 800 to 900 feet from the
entrance. Some were found on a colony of
'tubificid' worms in the sludge at the bottom of
the stream.

In the United States the molluscan fauna of
caves is rather limited and the majority of
species found are readily identified with those
living on the surface in the surrounding area.
Cave specimens are usually somewhat smaller
and have thinner, lighter-colored shells than
their .surface living relatives, but are otherwise
similar (Hubricht, 1940b). Land snails living
near the entrance or in the twilight zone are
probably deposited in the cave on debris carried
in by floods and it is doubtful if they are able
to maintain themselves for many generations
(Hubricht, 1941). Eighteen species and sub-
species of land snails have invaded the dark
zone of caves in Kentucky, Tennessee and
Alabama (Hubricht, 1964). Six of them (5
Hclicodiscus and Carychium stygium Call) are
known only from these caves. They were found
feeding on decaying plant material and the
guano of cave crickets. When discussing the
wide distribution of Carychium stygium in the
Kentucky caves, Hubricht (1960) stated that the
eyes of some specimens were somewhat reduced

Vol. 88 (3)

THE NAUTILUS

but he did not mention any other modifications
to cave life.

Freshwater snails, especially Hydrobiidae,
have become adapted to cave habitats and
viable colonies are found well-back in the dark
zone. A white, blind hydrobiid, Fontigens tar-
tarea, was described by Hubricht (1963) from
the stream in Organ Cave, Greenbrier Co., West
Virginia, and Culver (1970) reported it from the
"Greenbrier Caverns, the Hole (37° 56' 22" N;
80° 21' 12" W) and Martha's Cave." According
to J. R. Holsinger (personal communication)
large populations of troglobitic species of Foii-
tigen.<< have been found in the cave streams of
the Applachians in Virginia and West Virginia
but to date these have not been reported upon.
Hubricht (1940a, 1971) described three un-
pigmented, blind Amnicola and Antrobia culveri
(a new genus and species of blind
Hydrobiidae) from caves in the Ozark Plateau.

In 1950 he listed five species (two Amnicola
and uiidertermined species of Phi/i^a, Ferrisaia
and Musculium) as living in the dark zone of
these caves.

The small size of the species which have been
able to successfully invade and survive in caves
is undoubtedly a reflection of the scarcity of
food in such habitats. No suspension feeding
gastropods occur in such areas and among the
bivalves only the Sphaeriidae are found.

In addition to being unpigmented and being
one of the smallest species known, the Physa
collected by Dr. Holsinger appear to be making
modifications to cave life in the apparent reduc-
tion of the eye (see figure 19) proportionate
increase in size of radular teeth (figs. 14-15), and
an increase in the size of the embryo as evi-
denced by the size of the protoconch (Figs.
11-13). This large protoconch suggests that the
young are more developed at the time of hat-

Physa spelunca Turner and Cle)ich, new species.
FIG. 1. Holotifpe. FIGS. 2-9. Series of paratypes
to sfioir range of variation in the 75 specimens
collected. FIG. 3. the most elongate. FIG i. The
largest, thofivgh lacking the spire. FIG. 6. Side

view showing curvature of the lip. FIG. 7. Dor-
sal view of typical specimen. FIGS. 5 and 8.
Specimens showing thickening of the columella
area. FIG. 9. The smallest specimen collected.

82 THE NAUTILUS

July 22, 1974

Vol. 88 (3)

ching. Greater size would increase the mobility
and search-range of the young, and a more fully
developed radula' would increase the range of
food-particle size available U) it. Both these fac-
tors would enhance its chances of survival in
an environment where food is likely to be
limited.

This increase in embryo size agrees with the
findings of Poulson and White (1969) who
worked with cave fish and cave beetles. They
hypothesized that species which successfully in-
vade caves tend toward smaller population size,
lower reproduction rates, larger size at hat-
ching, late maturity and longer life. These
adaptions to a stable environment and low food
supply suggest that this new species is opting
for K selection as proposed by MacArthur and
Wilson (1967). They are also in agreement with
the Stability -Time hypothesis proposed by San-
ders (1968) for many deep-sea infaunal species.
Further research is needed to test this
hypothesis for cave snails but to our knowledge
this is the first time that such adaptations have
been noted for any troglobitic mollusk.

The fact that epigean species of Phym are
opportunistic probably allowed them to invade
this hot spring cave. They are small-sized
detritus feeders, capable of surviving under
varying conditions of temperature, salinity and
oxygen tension, as noted previously. These are
characteristics that would preadapt them for
the cave environment. Further adaptations, in-
cluding the larger size of the young on hatching
and the loss of eyes, are in agreement with the
theories of Barr (1968). Cave mollusks are ideal
organisms for evolutionary genetic studies such
as those of Avise and Selander (1972) on cave
fish of the genus Astyannx, but to date no
work has been attempted along these lines. The
large populations of Fontigevs in the caves of
Virginia and West Virginia mentioned by
Holsinger would provide material for such a
study.

Physa spelunca, new species
Figs. 2-9, 11, 14, 16-17, 19

Description Shell reaching 9 mm in length
and 4.5 mm in greatest diameter (a somewhat
larger, broken specimen has a body whorl length
of 7.8 mm and a width of 5.0 mm which would

Bs^4>4,^

O 1 mr

FIG. 10, Rndular teeth of Physa spelunca
showing long denticles and apaphi/ses. FIGS. Il-
ls. Com/xirative sizes of protoconchs in relation
to adult size. FIG. 11, Physa spelunca, adults
may reach about 11 mm in length, FIG. 12,
Physa virgata Gould, adidts reach 18 mm in
length. FIG. 13, Physa propinqua Tryon adults
reach 21 mm in length.

give a proportional total length of about 11
mm). Shell highly polished, white with a very
thin transparent periostracum; translucent,
fragile and smooth. Sculpture consisting of ex-
ceedingly fine growth lines only, with no
evidence of spiral sculpture. Whorls 4' 2 to 5,
rounded, rapidly increasing in size; body whorl
large, slightly shouldered: spire short, acute:
spire angle about 65° . Sutures moderately im-
pressed, aperture ear-shaped. Upper margin of
thin, outer lip inserting on the body whorl
well-below the periphery. Parietal callus thin to
rather thick in older specimens. Columella
oblique, curved, flattened and continuous with
the outer lip. Protoconch of about 1'^ whorls,
rounded, colorless and minutely malleated (see
figure 11). Radula with v-shaped rows of teeth,
typical of the genus, the formula being about
100-1-1(X) in the median portion (Fig. 10 and
Fig. 14).

Anatomical notes. Only preserved specimens
were available for study and these un-
fortunately were not in ideal condition. The
animal was a uniform whitish, the tentacles
short, broad and apparently lacking eyes at the
base. Histological sections, however, showed a
distinct eye cup but the retina was not
developed and the lens was apparently lacking.
A comparison of the eye of Physn heterostropha
Say with that of spelunca is shown in Figs. 18-
19. Digitiitions of the mantle were minute but

Vol. 88 (3)

THE NAUTILUS

this could have been a result of preservation.

Tlie digestive system appears typical for the
genus. The crop was packed with debris,
minute sand grains and what appeared to be
fungal hyphae. The reproductive system is
typical for the genus, the male portion being of
the 'Physodon' type as described and figured by
Clampitt (1970). The penis sheath is about %
the length of the praeputium, not constricted
and is unpigmented. The praeputium has a
slightly grayish tinge, and the praeputial gland
is located in the lower half. The vas deferens
is fine, about 4 times the length of the penis
sheath, and about one fourth was buried in
muscles of the body wall.

5.9

7.8

Length

Width

9.0 mm

4.5 mm

8.3

4.2

8.0

4.2

8.0

4.0

7.5

4.1

7.0

3.3

Transverse sections through posterior end of
the odontophore of (FIG. U) Physa spelunca
nnd (FIG. 15) Physa heterostropha Say shounng
the lateral incoiling of the radiila when retract-
ed. These specimens were preserved in alcohol
and had not been properly fixed for histological
work. The marked differences in shape may
well result from differences in fixation and
probably are of no taxonomic value. It is in-
teresting to note that the radular teeth of
spelunca from a specimen 6 mm long are
proportionally larger than those of
heterostropha from a specimen 12 mm long,
suggesting that the cave specimens may be
feeding on coarser material than surface living
species.

3.1

5.0 (broken specimen,
body whorl only)

Type locality. Cave stream, about 800-900 feet
from the entrance, in the dark zone, in Lower
Kane Cave, near Kane, about 12 miles east of
Lovell, on the east side of the Big Horn River,
Big Horn County, Wyoming, at 3,000 feet
elevation. Dr. John R. Holsinger, collector, June
18, 1969.

Repository of type specimens. Holotype,
Museum of Comparative Zoology no. 280016;
Paratypes MCZ nos. 280017-280019. Additional
paratypes from the same locality are in the
Museum of Zoology, Ohio State University;

prostate

pfoeputial
glo nd

Two views of male reproductive system of
Physa spelunca, typical of the "Physodon"
group. FIG. 16, Standard dorsal view. FIG. 17,
Specimen turned to right to show muscle at-
tachment.

84 THE NAUTILUS

July 22, 1974

Vol. 88 (3)

Museum of Zoology, University of Michigan:
United States National Museum, Delaware
Museum of Natural History and the Academy
of Natural Sciences of Philadelphia.

Remark.'^. Physa spelunca is characterized by
its transparent, colorless, highly-polished shell,
its relatively blunt apex and large colorless

0 I mm

rS'iv

-.r'

0 1 mm

Sections through the tentar.les ami eyes of
Physa heterostropha and Physa spelunca.
Speeimentt of both spedes were preserved hi
alcohol and had not been properly fixed for
histological work. Consequently the quality of
the sections is poor hnt they are comparable.
FIG. 18, Physa heterostropha, shouing the lens
and large heavily pigmented retina. FIG. 19,
Physa spelunca, lacking both the pigmented
retina and lens.

protoconch (see figure 11). Based on the
characters of the shell and the male reproduc-
tive system spelunca belongs to the "Physodon'
species group as modified from Baker (1928) by
Clampitt (1970). The whorls are shouldered, the
sutures impressed and the p)enial sheath of the
male is not constricted (Figures 16-17).

Baker (1928) described and figured the male
reproductive system of Physa integra Haldeman
and P. walkeri Crandall and placed them along
with other species, the anatomy of which was
unknown, in his group 'Physodon'. Clampitt
(1970) reported that P. michiganensis C\er\c\\ and
P. anntina Lea also had the 'Physodon' type
reproductive system and anatomical studies by
Te (1973) in addition to confirming Baker's
work on integra, showed that P. viiyata Gould
also belonged in this group. See Clampitt (1970)
for discussion of the status of 'Physodon'.

Both P. anatina and P. integra have been
reported from Wyoming (Henderson, 1918, 1936;
Beetle, 1961) and both bear resemblances to P.
spelunca. However, spelunca differs from them
in being colorless, transparent and nearly glass-
like; in lacking any indication of spiral sculp-
ture or of thickened opaque axial lines in-
dicating former margins of the lip. In addition,
the columella of spelunca is oblique and curved
rather than nearly straight, and the protoconch
is white rather than amber-brown.

Physa propinqua Tryon, P. gabbi Tryon and
P. coniformis Tryon, all closely related species
from the northwestern states and British
Columbia, are unknovm anatomically but, on
the basis of shell characters, could belong in
'Physodon'. Both propinqua and conifoi-nm dif-
fer from spelunca in having fine axial and
spiral sculpture, a straight columella, and in
having the lip extended anteriorly well-beyond
the base of the columella. Physa gabbi lacks
spiral sculpture but has pronounced axial
growth ridges, a strongly twisted columella, and
more acute spire. Physa imxjata Gould from
Arizona which is known to have the 'Physodon'
type anatomy also has both spiral and axial
sculpture as well as a strongly twisted
columella. All of these species have small dark
protoconchs.

Vol. 88 (3)

THE NAUTILUS

ACKNOWLEDGEMENTS

We are grateful to Dr. John R. Holsinger for
the receipt of the specimens and for data on
Lower Kane Cave; to George Te for discussions
on Pfu/sa classification; to Samuel L. H. Fuller
for preserved specimens of Phijsa heterastropha
Say, and to Edward Allen for histological work.

LITERATURE CITED

Avise, J. C. & R. K. Selander. 1972. Evolu-
tionary genetics of Cave-dwelling Fishes of

the genus Astyanax. Evolution 26: 1-19.
Baker, F. C. 1926. Nomenclatural Notes on

American Freshwater Mollusca. Trans.

Wisconsin Acad. Sciences Arts & Letters,

22: 193-205.
Baker, F. C. 1928. The Freshwater Mollusca of

Wisconsin, Part I. Gastropoda. Wisconsin Geol.

and Nat. Hist. Survey Bull. 70(1): 1-.507, pis.

1-28.
Barr, T. C. Jr. 1968. Cave ecology and the

Evolution of troglobites. Evolutionary

Biology 2:35-102 (Dobzhansky, Hecht, Steere,

editors).
Beetle, D. 1961. Mollusca of the Big Horn

Mountains. Nautilus 74: 95-102.
Brues, C. T. 1932. Further studies on the Fauna

of North American Hot Springs. Proc.

American Acad. Arts & Sciences, 67 (7):

185-303.
Clampitt, Phillip T. 1970. Comparative Ecology

of the Snails Physa gipina and Phijsa integm

(Basommatophora: Physidae). Malacologia

10(1): 113-151, figs. 1-15.
Culver, D. C. 1970. Analysis of simple cave

communities I. Caves as Islands. Evolution

24:463-474.

Hendei-son, J. 1918. A Mollusk hunt in

Wyoming. Nautilus, 32: 40-47.
Henderson, J. 1924. Mollusca of Colorado, Utah,

Montana, Idaho and Wyoming. University of

Colorado Studies 13: 65-223.
Henderson, J. 1936. Mollusca of Colorado, Utah,

Montana, Idaho and Wyoming — Supplement.

University of Colorado Studies 23: 81-145.
Hubricht, L. Apr. 1940a. The Ozark Amnicolas.

Nautilus 53(4): 118-122.
Hubricht, L. July 1940b. The Snails of Ted

Cave, Tennessee. Nautilus 54(1): 10-11.
Hubricht, L. 1941. The Cave Mollusca of the

Ozark Region. Nautilus 54(4): 111-112.
Hubricht, L. 1950. The Invertebrate Fauna of

Ozark Caves. National Speleological Society

Bulletin 12: 2 pages.
Hubricht, L. 1960. The Cave Snail,

Carijchium stijgium. Call. Trans. Kentucky

Acad. Sci. 21: 35-38.
Hubricht, L. 1963. New species of Hydrobiidae.

Nautilus 76(4): 138-140, pi. 8.
Hubricht, L. 1964. Land Snails from the Caves

of Kentucky, Tennessee and Alabama.

National Speleological Society Bulletin 26(1):

33-35.
MacArthur, R. H. and E. 0. Wilson. 1967. The

Theory of Island Biogeography. Princeton

University Press. 203 pages, 60 figures.
Poulson, T. L. and W. B. White. 1969. Tlie

Cave Environment. Science 165(3897): 971-980,

figs. 1-3.
Sanders, H. L. 1968. Marine Benthic Diversity:

A Comparative Study. The American Natural-
ist 102: 243-282.
Te, George A. 1973. A Brief review of the

Systematics of the Physidae. Malacological

Review 6: 61.

86 THE NAUTILUS

Julv 22. 1974

Vol. 88 (3)

NESOPUPA GALAPAGENSIS. A NEW INDO-PACIFIC
ELEMENT IN THE LAND SNAIL FAUNA OF THE GALAPAGOS ISLANDS

(PULMONATA: VERTIGINIDAE)'

Joseph Vagvolgyi

Department of Biology
City University of New York. N.Y. 10301

ABSTRACT

Nesopupa galapagensis, a new species of the pulmonate family Vertiginidae is
described from the Galapagos Islands. This is a new record of the genus Nesopupa,
typicalhi of Indo-Pacific distribution, in the Galapagos fauna.

INTRODUCTION

As the first part of a study of the evolution
and ecology of the land snails of the Galapagos
Islands, I have collected on the islands of Santa
Cruz (Indefatigable), Santa Maria (Floreana.
Charles), Isabela (Albemarle) and San Salvador
(Santiago, James) during the summer of 1970. Of
the material obtained, one finding will be
discussed below in detail, Nesopupa galapagenais.
because it represents a new species and a new
record of an Indo-Pacific genus in the Galapagos
land snail fauna.

DESCRIPTION

The shell: the height is 1.6 - 1.9 mm, the width
1.0 — 1.1 mm. the width — height ratio, .53 —

FIG. 1. Nesopupa galapagensis Vagvolgyi new
species. 1.9 mm Holotype.

.65; the height of the last whorl including the
aperture is 0.9 — 1.2 mm, that of the aperture
alone, 0.6 — 0.7 mm; in percentage of the total
height these values correspond to 53 — 67 and 35
— 41%, respectively; the whorl number varies
from 4' 4 to 5. The shape of the shell is nearly
cylindrical in 9 specimens, cylindrical-oval or
oval in the others; the whorls are convex, the
sutures deep, particularly so in the cylindrical
specimens; the last whorl ascends upon the
penultimate one prior to the aperture, slightly in
the oval specimens, more distinctly in the cylin-
drical ones. The umbilicus is minute. The aper-
ture is oval-triangular vdth a notch on the outer
lip formed by the inward and forward projecting
middle part of the outer lip (this region is

|90'4?W

w _

as3

' Contribution No. 134 from the Charles Darwin Research
Station. Santa Cruz. Galapagos. Ek^uador.

FIG. 1 Collecting sites on Isla San Salvador,
Giddpagos.

Vol. 88 (3)

THE NAUTILUS

sometimes termed "auricle"); the lips are slightly
reflected; the parietal wall is covered by a weak
callus that connects the origin of the outer and
inner lips; the lip swelling is weak but wide,
deeply receded from and parallel to the edge of
the lips; corresponding to the lip swelling there is
a weak and wide annular crest on the outside of
the shell. The armature consists of a parietal,
angular and columellar lamella and an upper and
lower palatal fold; the parietal lamella is large,
the angular, small; both lie moderately deep in
the aperture, and are separated from one
another; the columellar lamella is medium large,
deeply seated, its inner end is straight; the lower
palatal fold is large, the upper, medium to small,
both lie deep in the aperture; a sulcus may
mark on the outside of the shell the position of
either palatal fold. Sculpture: the embryonic
whorls are smooth (SOX magnification); the
postembryonic whorls have a fine striation and a
shiny, lustrous appearance except in the region of
the annular crest where the striation is coarser;
there is no sign of any pits. The color of the fresh
shell is dark brown, that of the folds and
lamellae, very light with a brownish tint.

Holoti/pe (fig. 1) and paratypes are deposited in
the collection of the Academy of Natural Sciences
of Philadelphia, nos. 332451, 332452, respectively.
Other paratypes in the collection of the Delaware
Museum, nos. 70650 and of the author. Type
locality: Peak 2974', central highlands of Isla San
Salvador (James Island), Galapagos Islands (fig.
2).

Material examined: Four samples, 2-32
specimens each, 38 specimens altogether.

DIFFERENTIAL DIAGNOSIS

Nesopupa (Infranesopupa) anceyana Pilsbry
and Cooke and N. (Infranesopupa) subcentralis
Pilsbry and Cooke of the Hawaiian Islands
closely resemble the new species in size (Table 1),
armature and sculpture; on this basis, N.
galapagensis is assigned to the subgenus /«-
franesopiipa. Both species differ, however, from
the new species in being more oval and having
shallower sutures, larger aperture and less
pronounced auricle. Another similar species is A^.
(Nesodagys) wesleyana Ancey, of the Hawaiian
Islands, which agrees with A^. galapagensis in
shape, convexity of the whorls and dentition

but has fine periostracal riblets and a very
weak auricle. However, the most similar species
is an undescribed one, from Surinam, Dutch
Guiana, South America, in the possession of the
Academy of Natural Sciences of Philadelphia;
the only difference is that the outline is a bit
more oval and the dentition a bit weaker than
in A^. galapagensis.

Some species of the genus Vertigo also closely
resemble A^. galapagenjns in shape, sculpture
and auricle but their dentition is different.

The new species does not show a great deal
of similarity to Nesopupa (Cocopupa) cocosensis
(Dall) of Cocos Island as one might expect from
the relative proximity of the areas of
distribution of the two species. Nesopupa
cocosensl^ is larger (Fig. 1) and has a pitted
sculpture.

ECOLOGY

Nesopupa galapagensis lives in the high and
moist central region of Isla San Salvador (fig.
2). It was found in the thickets and the open
fields as well. In the former it lived in the lit-
ter layer and the moss pads growing on trees,
in the latter, on the ground at the base of the
grass. The description of the collecting localities
follows:

Station 36. A few hundred yards from Peak
2974', on the southern slope, at about 2900' of
elevation. Good soil; impenetrable brush, com-
posed primarily of Psychotria nifipes and Tour-
nefortia rufosericea. Moss pads on the horizon-
tal branches of many trees (mostly belonging to
the species Zanthoxylum fagara). Four squares
of 25 X 25 cm each were sifted from the litter,
and 3 moss pads were taken without measuring
size. July 25, 1970.

Station 37a. Pampa or open grassy field at
the southern foot of Peak 2974', at about 2300-
2400' of elevation. Soil good, wet from several
days' drizzle (garua). Two samples of 25 X 25
cm were taken. The pampa habitat may be a
secondary one; according to some botanists,
pampas develop only when the original forest
cover is destroyed by the introduced goats,
pigs and cattle. July 30, 1970.

Station 38. Southwestern side of the crest
between Peaks 2974' and 2965', at about 2600-
2900' of elevation. Grass, bushes and the giant

88 THE NAUTILUS

July 22, 1974

Vol. 88 (3)

fern Cyathea make up the vegetation. Five sam-
ples of the usual size were taken, 2 from grassy
areas, 2 from the base of bushes and 1 from a
wash. Soil wet from garua. July 30, 1970.

Pilsbry noted (1920: 289) that species of In-
franesopupa are usually found on fronds of ferns
and leaves of low plants or occasionally on
trunks of trees. My observations that N.
galapagensis lives both on the ground and on
trees are in partial agreement with this.

DISTRIBUTION

Nesopupa galapagensis is endemic to the
Galapagos Islands. It is the only representative
of its genus there. Its apparent ancestors are
the species of Infranesopupa in the Hawaiian
Islands. It thus represents a new Indo-Pacific
element in the Galapagos land snail fauna.
Such elements are rare; the only other species
of Indo-Pacific relationships among the
Galapagos land snails is Tornatellides
chathamensis. Numerically the Indo-Pacific
elements represent somewhat less than 3% of
the fauna (2 sppcies of the total reported of 76;
based on Smith 1966). The majority of the
species are of Neotropical relationships.

The marine molluscs of the Galapagos mirror
this composition. According to Emerson (1967)
only 25 species or a little more than 4% of the
600 species reported have Indo-Pacific affinities.
The similarity may be merely coincidental,
however. On the one hand, the rarity of the In-
do-Pacific elements among the marine mollusks
— as Emerson argues convincingly — is due to
the scarcity of suitable habitats: coral reefs for
the reef dwellers common in the Indo-Pacific
region. His contention is supported by the fact
that Clipperton Island, which also lies in the
Eastern Pacific but is a coral atoll, has 47% In-
do-Pacific elements in its fauna. On the other
hand, the reason for the scarcity of the Indo-
Pacific elements among the Galapagos land
snails appears to be primarily the distance and
isolation from that region.

DISPERSAL

The Hawaiian Islands, where Nesopupa
galapagensi,s presumably originated, lie roughly
4000 miles northwest of the Galapagos Islands.

Geological evidence indicates no previous land
connection between the two archipelagoes or
between the Galapagos and the South American
mainland (McBimey and Williams 1969). Thus
Nesopupa galapagensis in all likelihood reached
the Galapagos Islands by overseas dispersal,
whether by ocean currents, winds, insects or
birds it is impossible to say. I do not believe,
however, that human introduction was respon-
sible, for two reasons. First, because the species
does not occur near human settlements or
cultivated areas, in disturbed habitats as in-
troduced species often do (e.g. species of
Subulina, Lamellaxis and Dernceras in the
Galapagos, Smith 1966); rather it occurs in
remote regions, in the litter layer and moss
pads which are undisturbed habitats. Another
habitat where it also occurs, the pampa, may
be a disturbed one; but even this habitat is far
away from human settlements. Second, because
the species has not been found on the
inhabited, cultivated islands of the archipelago;
rather, it has been found on San Salvador
which has been free of cultivation, although for
a while a salt mine was operated on its south-
western shore. Admittedly, future collecting
may discover the species on the inhabited
'islands as well and this fact may then refute the
argument. Another possible objection, namely
that San Salvador has some special ecological
setting which favors Nesopupa whereas the
other islands lack such seems to have no
validity at all as all the islands in question
have wet zones which at least in basic features
are counterparts of the wet zone of San
Salvador.

The process of overseas dispersal is generally
considered a fortuitous one and in our case it
indeed appears to be so. First, because
Nesopupa galapagemns, after having crossed a
vast extension of open ocean, only colonized one
of the 15 major islands of the Galapagos Ar-
chipelago, not the other 14. Second, it also
failed to colonize the relatively nearby Cocos
Island; the latter has been reached in-
dependently of N. galapagemns by another, not
closely related, species of Nesopupa, N. cocosen-
sis. Third, from the Galapagos the species made
another huge jump across 600 miles of open
ocean and 1200 miles of land to reach Surinam

Vol. 88 (3)

THE NAUTILUS

(refer tx> undescribed Nesupupa). This in itself
is remarkable as colonization usually proceeds
in the opposite direction, from the continents to
the islands. — It is possible that future collect-
ing will prove Nesopupa to be a more
widespread genus in South America than
hitherto assumed, in which case the origin of
the Galapagos Nesopupa becomes a mute
question. However, according to our present
knowledge, the Hawaiian origin appears more
probable.

ACKNO WLEDGEM ENTS

I gratefully acknowledge the assistance
received from the Research Foundation of the
State University of New York. I also thank
Messrs. Roger Perry and Rolf Sievers of the
Charles Darwin Research Foundation for their
help during our stay on the islands, Mr. Daniel
Weber of the same institution for identifying
several plants, my wife Alice for help in the

field work and Dr. Robert Robertson for
allowing me to use the collection of the
Academy of Natural Sciences of Philadelphia
for comparisons.

AMERICAN MALACOLOGICAL UNION
40th ANNUAL MEETING

Springfield, Massachusetts, will be the site of
this summer's annual meeting of the A.M.U.,
from Saturday, August 3, 1974 (preliminary
registration, 2:00 to 5:00 p.m.) through Wed-
nesday, August 7; to be held in the Museum of
Fine Arts and the Museum of Science in down-
town Springfield. 1974 President is Harold D.
Murray, Biology Dept., Trinity University, San
Antonio, Texas 78284; local host is Earl H.
Reed, Museum of Science, 236 State St.,
Springfield, Mass. 01103.

INDO-PACIFIC
MOLLUSCA

MONOGRAPHS OF THE MARINE MOLLUSKS OF
THE WORLD WITH EMPHASIS ON THOSE OF
THE TROPICAL WESTERN PACIFIC
AND INDIAN OCEANS

The most technical and most beautifully illustrated
journal now being published on Recent and Tertiary
marine moUusks. Over 20 professional malacologists are
currently contributing. Edited by R. Tucker Abbott.
Among the groups treated are Strombidae, Cassidae,
Tridacnidae, Turridae, Littorinidae, Phasianellidae, and,
soon to come, Patellidae, Harpidae and Mitridae.

Issued to date in looseleaf form with three sturdy,
permanent binders — 1100 pages, 810 plates (31 in full
color). Limited number of complete sets left, $91.90 U.S.
(foreign: $94.00), postage paid. Any number of extra
binders available at $6.00.

Published by
The Delaware Museum of Natural History, Box 3937, Greenville, Delaware 19807 U.S.A.

90 THE NAUTILUS July 22. 1974

NEGLECTED PAPERS ON NAIADES BY W. I. UTTERBACK

Samuel L. H. Fuller

Academy of Natural Sciences of Philadelphia
Philadelphia, Pennsylvania 19103

Vol. 88 (3)

To the list of papers on naiades by W. I. Ut-
terback which was compiled by Johnson (1969)
may be added the following, less familiar work.

1928. Phylogeny and ontogeny of naiades. Pro-
ceedings of the West Virginia Academy of
Science 2: 60-67.

This paper is primarily a recapitulation of
the naiad classification initiated by Ortmann
(1910). Since Utterback provides no references
to authorities other than himself, it is im-
possible to ascertain the source(s) of some of his
more intriguing remarks, such as the statement
that Cumberlandia monodonta (Say) can
produce two broods of glochidia in a single
summer. Noteworthy contributions are a
description of volvocoid naiad sperm bodies (see
Utterback, 1931) and a discussion of some
remarkable aspects of the biology of
Megalonaias gigantea (Barnes). The latter con-
tribution offers no advance over Utterback
(1915-1916) or the earlier account by Howard
(1914).

1930. A new genus of freshwater mussels
(naiades). Ibid., 4: 66-69, text figures 1-3.

This paper is a discussion of Utterbackia,
which Baker (1928) had already described and
based on Anodonta imbecilis Say. Superior
notes on the natural history of this species had
been provided by Allen (1924) and Tucker (1927,
1928).

1931. Sex behavior among naiades. Ibid.,
5: 43-45.

Little advance is made beyond Utterback's
(1915-1916, 1928) earlier works.

1933. New glochidia. Ibid., 6: 32-36, text figures
A-C.

Descriptions and discussions of the glochidia
of seven naiad species and alleged subspecies
are given. Much of this information had not
previously been published.

REFERENCES CITED

Allen, E. 1924. TTie existence of a short repro-
ductive cycle in Anodonta imbecilis. —
Biological Bulletin 46: 88-94.

Baker, F. C. 1928. The fresh water Mollusca
of Wisconsin. Part II. Pelecypoda. — Bulletin
of the Wisconsin Geological and Natural
History Survey, No. 70: 1-495.

Howard, A. D. 1914. Ebcperiments in propagation
of fresh-water mussels of the Quadrula group.
Appendix IV to the Report of the United
States Commissioner of Fisheries for 1913:
1-52. Separately issued as Bureau of Fisheries
Etocument No. 801.

Johnson, R. I. 1969. The Unionacea of William
Irvin Utterback. The Nautilus 82: 132-135.

Ortmann, A. E. 1910. A new system of the
Unionidae. The Nautilus 23: 114-120.

Tucker, M. E. 1927. Morphology of the
glochidium and juvenile of the mussel
Anodonta imbecilis. Transactions of the
American Microscopical Society 46: 286-293.

Tucker, M. E. 1928. Studies on the life cycles of
two species of fresh-water mussels belonging
to the genus Anodonta. Biological Bulletin
54: 117-127.

Utterback, W. I. 1915-1916. The naiades of
Missouri. American Midland Naturalist 4:
41-53, 97-152, 181-204, 244-273, 311-327.
339-354, 387-400, 432-464. Repaged and re-
printed in 1916 by University of Notre Dame
Press, Notre Dame, Indiana, pp. 1-200.

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MOLLUSK VOUCHER SPECIMENS

It is becoming increasingly important for future
research purposes that an identified sampling of
species mentioned in pubUcations be deposited in
a permanent, accessible museum speciaUzing in
moUusks. This is particularly true of inollusks used
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OCTOBER 1974

THE

NAUTILUS

Vol. 88
No. 4

A quarterly

devoted to

malacology and

the interests of

conchologists

Founded 1889 by Heni-y A. Pilsbry. Continued by H. Burrington Baker.
Editor-in-Chief: R. Tucker Abbott

EDITORIAL COMMITTEE

CONSULTING EDITORS

Dr. Arthur H. Clarke, Jr.
Department of Mollusks
National Museum of Canada
Ottawa, Ontario, Canada K1A-0M8

Dr. WUliam J. Clench
Curator Emeritus
Museum of Comparative Zoology
Cambridge, Mass. 02138

Dr. William K. Emerson

Department of Living Invertebrates

The American Museum of Natural History

New York, New York 10024

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Department of Living Invertebrates

The American Museum of Natural History

New York, New York 10024

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Department of Geology
The Ohio State University
Columbus, Ohio 43210

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Los Angeles County Museum of Natural History
900 Exposition Boulevard
Los Angeles, California 90007

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Biological Laboratory
National Marine Fisheries Service
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Division of Marine Geology

School of Marine and Atmospheric Science

10 Rickenbacker Causeway

Miami, Florida 33149

Dr. Joseph Rosewater
Division of Mollusks
U. S. National Museum
Washington, D.C. 20560

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Department of Invertebrates
Field Museum of Natural History
Chicago, Illinois 60605

Dr. David H. Stansbery
Museum of Zoology
The Ohio State University
Columbus, Ohio 43210

Dr. Ruth D. Turner

Department of Mollusks
Museum of Comparative Zoology
Cambridge, Mass. 02138

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Division of Biology

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EDITOR-IN-CHIEF

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THE
NAUTILUS

Volume 88, number 4 — October 25, 1974

CONTENTS

Richard W. Fullington

Two New Land Gastropods from Texas (Zonitoides and Stenotrema) 91

Artie L. Metcalf

Peripheral Species of the Oreohelix metcaifei Cockerell Complex

(Pulmonata: Oreohelicidae) 94

E. H. Michelson and Lorin DuBois

Lymnaca emarginata, a Possible Agent for the Control of the

Schistosome-Snail Host, Biomphalaria glabrata 101

G. L. Mackie, S. U. Qadri and A. H. Clarke

Development of Brood Sacs in Musc7dmm securis (Bivalvia: Sphaeriidae) 109

R. A. Fralick, K. W. Turgeon and A. C. Mathieson

Destruction of the Kelp, Laminaria, by Lacuna vincta (Montagu) 112

David J. Prior

Role of the Incurrent Slphonal Valve in the Surf Clam,

Spisula solidissima (Mactridae) 115

Donald W. Kaufman

Second Locality Record for Mesodun ieatherwoodi Pratt 118

Book Reviews

(of) M. P. and M. H. Oliveira, 108; H. B. Stenzel, 117; G. A. Solem, 120; News 119

Just
Published-

Latest edition of the
"bible of shell manuals"

American
Seashells

670 pp .

5,050 illus..

8V2 X 1 1

AMERICAN SEASHELIS

Second Edition
By R.Tucker Abbott

This updated edition includes more species of
shells than any other book currently in print in the
English language. It lists all 6500 known species
of marine mollusks living in the waters adjacent to
North America. Shown and described in detail are
over 3000 of them. Enlarged from the first edition
to cover four times as many species, American
Seashells explains the habits, foods, identification
features, methods of growth, life histories, geo-
graphical distributions, bathymetric ranges and
other biological facts concerning the rarest, as
well as the most common, marine mollusks. Abun-
dantly illustrated with magnificent color plates, this
outstanding reference book also brings you the
secrets of shell collecting, techniques in caring
for the collection, and methods of study.

At your bookstore, or write to publisher
below lor further information

Dept.LR

Van Nostrand Reinhold Co.

450 WEST 33HD STREET, NEW YORK. NEW YORK 10001

2SB

Vol. 88 (4)

THE NAUTILUS

TWO NEW LAND GASTROPODS FROM TEXAS (ZONITOIDES AND

STENOTREMA)

Richard W. P^ullington

Dallas Museum of Natural History

Fair Park Station

Dallas. Texas 75226

ABSTRACT

Zonitoides kirbyi fZonitidae) is described from Schulze Cave, approx. 28 miles
northeast of Rocksprings. Edwards Co., Texas. It is most closely related in form
to Zonitoides arboreus (Say) but differs by being larger and glossier uith less
distinct growth lines. Stenotrema leai cheatumi (Polygyridae) is described from
Palmetto Stute Park, Ottine, Gonzales Co., Texas. It diffeis from the most
closely related species in form Stenotrema leai leai (Binney) by being much
smaller, more depressed, and uith a much larger fulcrum.

An undescribed zonitid was sent to the late
Dr. E. P. Cheatum by Dr. Walter Dalquest of
Midwestern University, Wichita Falls. Texas.
The fossil shells were collected by Dr. Dalquest
and his colleagues in Schulze Cave which is
located approximately 28 miles northeast of
Rocksprings, Edwards County, Texas. Living
specimens were later obtained from the site by
the author. Dr. Dalquest's report on the
statigraphy and vertebrate remains found in
the cave, was published in 1969.

According to their report, the cave is of the
sinkhole type and "probably formed by solution
from a vertical tissue that penetrated two
limestone layers of the Upper Cretaceous Ed-
wards formation." The shells were found in
association with mammalian bones in a zone of
matrix designated as layer C. Many of the
shells were stained by yellowish sediments. A
part of a bone from a grizzly bear, in this
same layer, was sent to the Socony-Mobil
Laboratories in Dallas, Texas for dating. The
C14 test revealed an age of 9,680 ± 700 years
BP, which indicated a late Pleistocene age.

On July 25, 1972, a collecting trip was made
by the writer accompanied by Dr. E. P.
Cheatum and Wayne Seifert, staff member of
the Dallas Museum of Natural History that
sponsored the trip. The main purpose of the
trip was to ascertain if the species still lived in
the cave and if it was extant in the surround-

ing environs. Equipped with headlights. Seifert
and myself entered the cave and, in the same
zone from which the fossil shells had been
collected, we found living specimens of this
species. The living snail is described as follows:
the entire pale-grey body was visible through
the transparent shell. Each transparent eyestalk
was capped by the dark eye. The cave was
damp and fungal growths were abundant. Un-
fortunately, only one living snail was collected
and this was an immature form with a shell
diameter of 3.19 mm. A diligent search was
made of the area surrounding the cave in hopes
that we could find the living snail or at least
dead shells of this species. None were found, so
the origin of this snail remains a puzzle.

This species is named for Mr. Hal P. Kirby,
Director of the Dallas Museum of Natural
History who has encouraged and greatly aided
Molluscan research in the Southwest.

Zonitoides kirbyi neiv species
Figs. 4-6

Description-Shell pale, glossy, translucent, and
weakly sculptured with rather evenly-spaced
but crowded growth lines which are more
pronounced on the basal whorl. Under
magnification, fine parallel striae are visible on
the upper surface of the whorls exclusive of the
embiyonic whorl which is smooth. The striae,
although present on the lower surface of the

92 THE NAUTILUS

October 25, 1974

Vol. 88 (4)

FIG. 1-3. Zonitoides arboreus (Say); x J^.3;
FIG. i-6. Zonitoides kirbifi n. sp.; x 3.8; FIG. 7-
.9, Stenotrema leai cheatumi n. mbttp.; x 2.6;
FIG. 10-11. Stenotrema leai leai (Binney); x 2.2;
FIG. 12-13, Stenotrema leai alidae (Pilsbry); x
2.9.

whorls, are more subdued. The umbilicus is con-
tained approximately 3.2 times in the shell
diameter. The whorls are well-rounded, the aper-
ture is ovoidal and the peristome is thin.
Measurements in mm. of holotype: diameter:
6.3: height: 3.4; aperture height: 2.04; aperture
width: 1.53.

Holotype: No. 3286 Dallas Museum of
Natural History; paratypes in Delaware Mus.
Nat. Hist. No. 72862; paratypes will be
deposited in the National Museum of Natural
History, Carnegie Museum, Museum of Com-
parative Zoology, Academy Natural Sciences of
Philadelphia, and the Museum of Zoology,
University of Michigan. Type locality: Schulze
Cave, Edwards Co., Texas, July 25, 1972.

Discussion — Zonitoides kirbifi is most closely
related in form to Zonitoides arboreus (Say)
(figs. 1-3), but differs in several respects. Z. kir-
biji is much larger and glossier with less distinct
growth lines. It also has a much larger um-
bilicus which abruptly expands in the last
whorl. The aperture is very ovately-lunate and
not deeply rounded - as in Z. arboreus.
Zonitoides arboreus abounds in the area im-
mediately surrounding the cave and only dead
shells were found inside the cave. Z. kirbifi (live
& dead shells) is found only in the cave. It ap-
pears that Z. kirbiji may be a form of Z. ar-
boreus that has been microgeographically
isolated long enough to become a separate
species.

Stenotrema leai cheatumi new subspecies

Figs. 7-9

An undescribed polyg>'rid was collected by
Dr. E. P. Cheatum and myself in Palmetto
Park at Ottine, Gonzales County, Texas, on
November 11, 1971. The locality is an
ecologically isolated area that is low, swampy
and thickly studded with shrubs and trees.
Palmetto plants are extremely abundant. The
surrounding environment is typical of the
Texan Biotic Province as defined by Blair
(1952) but being much drier. The undescribed
snails were abundant on the moist ground un-
der palmetto plants and under rotten logs.

Description — The shell is umbilicate, with a
low, convexly conoid spire and 5.5 rather
closely-set whorls. Except for the embryonic

Vol. 88 (4)

THE NAUTILUS

whorl, the remaining whorls are covered with
irregularly-placed growth lines which, although
not coarse are more conspicuous on the basal
whorl. Under magnification the embtyonic
whorl is beset with fine radiating lines crossed
by delicate striae confined to the embr>'onic
whorl; a few very short hairs are present on
the ventral surface of the basal whorl and on
the upper surface of the last two whorls. The
aperture length is 4.25 mm., and the slightly
curved white parietal tooth is 2.38 mm. long,
resting obliquely on the exceedingly thin
parietal callus. The umbilicus is openly per-
forate with the exception of a flare-out of the
lower lip which covers the inner edge of the
umbilicus. The white peristome is thickened
within and reflected on its outer and inner
margin thus leaving a conspicuous groove just
back of the outer lip. The umbilicus is con-
tained approximately five times in the shell
diameter. A large white rounded fulcrum is
present which extends fi'om the top of the basal
whorl to its floor. Holotype measurements in
mm.: diameter: 8.2; height: 4.6; No. of whorls:
5.5.

Holotype: No. 3288 Dallas Museum of
Natural HistoiT; paratxTDes in the Delaware
Mus. Nat. Hist. No. 72861; paratypes will be
deposited in the National Museum of Natural
History, Carnegie Museum, Museum of Com-
parative Zoologv', Academy Natural Sciences of
Philadelphia, and the Museum of Zoology,
University of Michigan. The t\T)e locality is
Palmetto Piirk, Ottine, Gonzales Co., Texas.
November 11, 1971.

Discussion — Stenotrema leai cheatumi is
most closely related in form to Stenotrema leai
leai (Binney) (fig. 10-11). Stenotrema I. cheatumi
differs in the following respects: it is smaller,
more depressed than S. I. leai and has, on the
average, fewer whorls, is much less hirsute, and
has a much larger fulcrum. Radially-lengthened
granules are absent on the embrj-onic whorls
but cross-striae are present. S. I. cheatumi dif-
fers from S. leai aliciae (Pilsbn,-) (fig. 12-13), in
the same features that differentiate it from 5.
I. leai.

The Stenotrema leai complex is as yet
unresolved. Pilsbry (1948) made S. monodon
(Rackett) synonomous with S. leai. Pilsbry in
1940 differentiated & leai leai from S. leai
aliciae in that, "the parietal tooth is higher in
S. monodon, and the axial end continues in a
tapering ridge, at the end curving partly
around the axis." S /. leai is also separated
from 5. /. aliciae by its open umbilicus while
the umbilicus of S /. aliciae is generally im-
perforate. In Texas, 5. leai leai is usually found
only as a fossil, while S. /. aliciae is usually
found only in the living state (Cheatum and
Fullington, 1971). In almost any series from the
same locality, variants may be found that con-
form to either 5. /. leai or S. I. aliciae. Due to
these facts, I am giving S. leai cheatumi only
subspecific rank until the Stenotrema leai com-
plex is further studied.

I am naming this subspecies in honor of the
late Dr. E. P. Cheatum. This article was ac-
tually begun by him but he was unable to
finish it. The work on the two gastropods
named here was the last of many such en-
deavors accomplished by Dr. Cheatum.

LITERATURE CITED

Blair, W. F. 1950. The Biotic Provinces of

Texas. Te.xas Jour. Sci. 2(1): 93-117.
Cheatum, E. P. & R. W. Fullington. 1971. The

Recent and Pleistocene Members of the

Gastropod Family Polygyridae in Texas.

Dallas Museum of Natural History, Bulletin

I, Part I, pp. 41-43.
Dalquest, W., Edward Roth and Frank Judd.

1969. The Mammal Fauna of Shulze Cave,

Edwards County, Texas. Bulletin Florida

State Museum, 13 (4): 205-276.
Pilsbry, H. A. 1940. Land Mollusca of North

America (north of Mexico). Acad. Nat.

Sci., Philadelphia, Monograph no. 3, 1 (2):

676-681.
PilsbiT, H. A. 1948. Land Mollusca of North

America (north of Mexico). Acad. Nat.

Sci., Phildelphia, Monograph no. 3, 2(2):

1099.

94 THE NAUTILUS

October 25, 1974

Vol. 88 (4)

PERIPHERAL SPECIES OF THE OREOHELIX METCALEEI
COCKERELL COMPLEX (PULMONATA: OREOHELICIDAE)

Artie L. Metcalf

Department of Biological Sciences
University of Texas at El Paso 79%8

ABSTRACT

New data is presented concerning past and present distribution of land
snails of the Oreohelix metcalfei Cockerell complex, especially as regards species
on the periphery of the range of the complex. Two new species are described:
Oreohelix caballoensis and 0. confragosa. Some trerds concerning evolution of
the shells are noted.

INTRODUCTION

Treated herein are several taxa of the
Oreohelix metcalfei Cockerell complex of land
snails (Pulmonata: Stylommatophora:

Oreohelicidae). These taxa occur, living and
fossil, in several mountain ranges of south-
central New Mexico and seem restricted to
areas of limestone bedrock. 0. metcalfei was
described by Cockerell as a subspecies of 0.
strigosa (1905:113-114) from a specimen collected
by 0. B. Metcalfe from "Mountains near
Kingston, New Mexico," in the east-central
foothills of the Black Range in Sierra County
(Fig. 1). 0. B. Metcalfe (not to be confused with
the present author) collected botanical and
other specimens in south-central New Mexico in
the early 190()'s. Pilsbr>' (1939:509-514) re-
cognized several subspecies of 0. metcalfei and
one related species as appertaining to the com-
plex.

Major aims here are to present additional
data regarding the distribution of the complex
and to point out the existence of fossil
localities, of small extent areally and easily
overlooked. Hopefully this may contribute to an
eventual thorough analysis of the entire 0. met-
calfei complex. Such an undertaking would
require much additional field work in the fast-
nesses of the Black R;inge (Fig. 1) where access
is largely by hiking and horseback. This Range
comprises the Black Range Primitive Area of
approximately .300 square miles plus an area of
approximately equal extent outside the

Primitive Area. Until such time as a definitive
analysis is undertaken it remains highly
problematic as to which taxa in the complex
more properly deserve specific recognition and
which should only be considered subspecies of
0. metcalfei This is, of course, a common
problem in the systematics of montane snails,
which in their evolutionary zeal have taken lit-
tle heed of the strictures of binomial or
trinomial nomenclature. Herein two new names
are provided chiefly as a utilitarian measure to
facilitate future revisions. As a practical ex-
pedient, I refer to species rank several kinds
from mountains or mountain groups peripheral
to the Black Range (Fig. 1) and separated from
it by extensive intermontane basins. Variants
from the Black Range itself are considered as
comprising a number of subspecies of 0. met-
calfei as treated by Pilsbry (1939) for all taxa
of the complex except 0. pilsbryi Ferriss, which
he relegated to species rank.

I thank Mr. William de Socarraz for
preparation of micrographs and Drs. Arthur H.
Harris and Richard D. Worthington for
providing me with some of the specimens
reported.

Abbreviations used for museums in which
materials have been deposited are: AN-
SP = . Academy of Natural Sciences of
Philadelphia; DMNH = The Delaware Museum
of Natural History; MALB = Museum of Arid
Land Biology, The University of Texas at El
Paso.

Vol. 88 (4)

THE NAUTILUS

DESCRIPTIONS OF NEW SPECIES

Oreohelix caballoensis yiew species

Figs. 2, 3

Desicription of Holotype: (Fossil shell, ANSP
332307) Shell heavy, moderately elevated, convex
dorsally and ventrally, 19.4 mm in diameter
and 12.0 mm in height; slightly angular
peripherally; last whorl descending markedly to
aperture; aperture 9.0 mm wide and 8.1 mm
high; umbilicus relatively narrow, 6.0 mm wide,
contained 3.2 times in diameter; relatively
tightly whorled. wdth 5.15 whorls; embryonic
whorl with low, regular wrinkles, grading to
low, regularly-spaced riblets on second whorl,
remainder of dorsal surface with low, irregular
growth striae, becoming coarser towards aper-
ture; ventral surface relatively smooth except
for occasional growth striae (spiral striae not
observed); shell generally white but light tan on
first 2^2 whorls dorsally and with two reddish
brown bands, one immediately below peripheral
angularity on body whorl, intersecting upper
edge of lip and obscured from that point on,
proximally; the other a lighter spiral band in
center of dorsal whorls from beginning of whorl
three, distally, fading near aperture on body
whorl. Type locality. Locality 1 in "List of
Localities," hereafter, and in Fig. 1.

Variation: (Paratypes: DMNH 70647 and
MALE 3343, Loc. 1; ANSP 332308 and MALE
3631, Loc. 2). Only three entire mature shells
and several broken shells were obtained at the
type locality (Loc. 1). Paratypes (also fossil)
from Locality 2, in the lower western foothills
of the Caballo Mts., seem to have been slightly
smaller at maturity with more tightly whorled
shells. For ten specimens from this locality,
diameter/number of whorls averaged 3.22, while
three measurable specimens from the type
locality averaged 3.46. Umbilicus is relatively
larger for specimens from Locality 2, with
diameter/width of umbilicus averaging 3.27 for
ten specimens against 3.89 for the three
specimens from Locality 1.

Comparisons: Compared to the subspecies of
0. metcalfei 0. caballoensis most resembles 0.
m. hermosensis Pilsbry and Ferriss and 0. m.
cuchillensis Pilsbry and Ferriss. These kinds are
from northeastern foothills of the Elack Range

and the nearby Cuchillo Mts. (Fig. 1), ca. 30
miles northwest and north-northwest, respec-
tively, of the northern part of the Caballo

FIG. 1. Map of south-central New Mexico in-
dicating features mentioned in text. Cantovr-s at
5000. 7000 and 9000 feet indicated by contour
lines, uith elevations between .5000 and 7000 feet
dotted and elevations above 9000 feet bkwk.
Resenums on Rio Grande iiidicated by wavy
lines. Localities mentioTied are indicated by
number and black dot. Inset at lower light is
of central and noi-ther-n pari of Caballo Mts.
(.5000 and 7000 feet contour lines indicated) and
of Caballo Reservoir.

Abbreviations: BP— Brushy Peak of Caballo
Mts.: C Res. = Caballo Reservoir: E B
Res. = Elephant Butte Reservoir: M=Mountmns:
Mag. M.=Magdalena Mts.; PAM=Pinos Altos
Mts.: THM=Tres Hermanas Mts.

96 THE NAUTILUS

October 25, 1974

Vol. 8X (4)

Range and seem a likely source for propagules
reaching the Caballos. Shells of 0. m. her-
mosensis and 0. m. curhillensis are, however,
more depressed with a slightly larger umbilicus
than in 0. cahalloensis.

Etjfmolofjii: From Cabnilo (Sp., horse), in
reference to the Caballo Mts., in which the
species occurs.

Oreohelix confragosa new species

Figs. 4-7, 9

Desicription of Holotypp: (Fre.sh shell with
desiccated soft parts, ANSP 332309). Shell

hea\7, convex dorsally and ventrally, 17.7 mm
in diameter and 10.3 mm in height, bearing
rounded keel peripherally at ca. mid-height,
keel reduced to an angularity on distal-most
part of body whorl, keel bordered by spiral, oc-
casionally coarsely punctate grooves above and
below, these also fading out on last ' 4 of body
whorl; aperture round except for slight
angularity in outer lip at position of keel, 8.2
mm wide and 8.3 mm high; umbilicus relatively
narrow, 4.7 mm wide, contained 3.8 times in
diameter; 5 whorls; embryonic whorl with
regular, smoothly arcuate wrinkles, these

FKJS. 2. -i. Holotupe of Oreohelix caballoen-
sis n. Ap.. (194 'mm diameter). FIG. h- Em-
bryonic whorls of Oreohelix confragosa n. sp.
(scanning electron micrograph. l(X)X). FIGS. 5,
6. Holotype 0/ Oreohelix confragosa n. sp.. (17.7
mm dia.meter). FIG. 7. Fossil .'Specimen of
Oreohelix confragosa n. sp. from Locality A,
(17.6 mm diameter). FIG. 8. Fossil specimen of

Oreohelix florida Pilsbry from Tres Hoynanas
Mtf!.. Locality 6. (16.6 mm diameter). FIG. 9.
Apiccd whorls of Oreohelix confragosa n. sp.
(scanning electron micrograph. .V)X). FIG 10.
Fossil specimen of Oreohelix florida Pilsbry
from Cooke Range, Locality 5, (21.1 mm
diameter).

Vol. 88 {\)

THE NAUTILUS

wrinkles becoming liigher and sinuous at 1 to
m whorls (sinuosity in riblets caused by their
intersection with two very low spiral ridges and
with the spiral groove atop keel), wrinkles
grading into sharp, well-defined riblets at 1^4 to
2V2 whorls, these riblets fading out at 2';; to
2^/4 whorls with irregular coarse growth
wrinkles on remaining whorls dorsally; ex-
ceedingly fine, close-spaced spiral striae visible
at many places on both dorsiil and ventral sur-
faces of shell; irregularly round to elongate
scattered pits on both surfaces; coarse growth
wrinkles on ventral surface; shell generally
whitish, with extremely faint, diffuse, grayish
brown band immediately below keel on
proximal half of body whorl, covered proximally
by upper margin of lip; a few light gray spots
on ventral surface with a faint, shadowy, gray
spiral band (with interruptions) on proximal H
of body whorl; dorsally, initial 2'/2 whorls light
grayish brown, irregular gray to brownish gray
splotches on whorls 2*2 to 4 and a few gray
spots on proximal part of body whorl. Type
locality. Locality 3 in "List of Localities" and
in Fig. I.

Genitalia: (Data from paratypes from
Locality 3; see Fig. 11). Penis swollen in middle
part but narrowed distally, bearing a small
lateral cornuted appendix distally; internally,
wall of proximal 45% bears fleshy longitudinal
folds, while that of the distal 55% bears
"checkrows" of small quadrate papillae, except
for one longitudinal groove that is free of
papillae; area of tract joining penis to
epiphallus slightly inverted back into penial
cavity; retractor muscle strands attached to
both penis and epiphallus at their area of junc-
ture; epiphallus short and stout and vas
deferens relatively short as in 0. metcalfei
radiata and 0. pilsbnfi (Pilsbry, 1939; Fig. 331);
free oviduct short, talon darkly pigmented.
Lengths for some organs for three specimens
with shell diameters of 14.0, 14.5 and 17.3 were,
respectively: penis: 6.4, 7.5, 8.2; epiphallus: 2.2,

2.6, 2.5; vas deferens: 4.7, 6.5, 5.9; vagina: 2.4,

2.7, 3.3; free oviduct: 1.7, 1.5, 2.1; spermathecal
duct and sac: 7.8, 8.4, 11.5.

Variation: (Paratypes: ANSP 332310, DMNH
70649, Dallas Museum of Natural History 3867,
MALB 3495, Locality 3; ANSP 332311 and

MALB 3494, Locality 4). For 30 paratypes from
the type locality (Loc. 3) the following propor-
tions were obtained (mean outside parenthesis;
range inside parenthesis): Diameter/number of
whorls: 3.54(3.16-4.02); Diameter/width of aper-
ture: 2.34(2.12-2.50); Diameter/height of aper-
ture: 2.33(2.14-2.63); Diameter/lieight of shell:
1.76(1.53-1.97); Diameter/width of umbilicus:
3.67(3.32-4.19). Proportions of fossil shells from
L<_)cality 4 are similar to the above but shells
are slightly less tightly coiled, more depressed
and with relatively larger apertures but smaller
umbilici. For 20 specimens from Locality 4
proportions were: Diameter/number of whorls:
3.42(3.01-4.01); Diameter/width of aperture:

2.5 mm

FIG. 11. A. Genitalia of Oreohelix confragosa
new .ipecies (paratype and topotype). Ab-
breviations: a=atrium: e= epiphallus; hd=/ier-
maphroditic duct; lp= lower pari of penis;
o=free oviduct; p=prostate; pr=penial retrac-
tor: sd= spermathecal duct; t = talon;
a = uterus; uii= upper part of penis; \ = vagina;
vd = vas deferens.

B. Longitudinal section of penis nf 0. con-
fragosa showing lou:er. costulate and upper
papillose areas, diverted distal end and small
l(it( rol appendix.

98 THE NAUTILUS

October ^5, 1974

Vol. 88 (4)

2.12(1.98-2.39); Diameter/height of aperture:
2.17(2.01-2.39); Diameter/height of shell:
1.81(1.62-2.01); Diameter/width of umbilicus:
3.83(3.40-4.50).

Fossil shells from Locality 4 retain, even in
their fossil condition (Fig. 7), a well-defined
reddish brown band below the keel. An
equally well-defined brownish band is located
centrally on the dorsal surface of all whorls
succeeding the first two. A brown band is also
found below the keel on younger (up to en. 4)
whorls on living (topotypic) specimens. In larger
living specimens the ultimate (usually fifth)
whorl covers much or all of this band. On
younger shells, also, a dim brown band is ob-
servable on the upper surface of whorls as in
fossils from Locality 4. This band fades with
age, however, and is usually indiscernible on
older shells. In regard to banding, then, living
specimens seem ontogenetically to pass through
a stage when they resemble the fossil specimens
from Locality 4 as well as the more heavily
banded "peripheral" species mentioned hereaf-
ter. Pilsbry (1939:413) discussed loss of the sup-
posedly primitive bands in some kinds of
Oreofielix.

Embryos closely resemble those figured by
Pilsbry (1939: Fig. 333) for 0. m. radiata and
0. m. herynosensk. Young shells up to ca. two
whorls bear several spiral rows of hairlike
cuticular processes ventrally and on the keel
and on each of two or three low spiral ridges
dorsally (ridges observable in left part of Fig.
9). Short cuticular hairs are also produced on
the keel of the third whorl and these persist in
the shelter of the sutural depression on
specimens up to 15 mm in diameter. Fig. 4 in-
dicates presence of minute pustules on dorsal
surface of the embryonic whorl at its origin.

Shells commonly exhibit rough radial
corrugations and areas in which the outermost
shell layers are broken or missing. Pits, scars
and other irregularities also are common, these
accumulating and becoming especially noticeable
in older shells. The common occurrence of such
areas suggested the name confragosa. L.,
broken, rough, uneven.

Comparisons: 0. cor\fragom seems closer to
the nominal subspecies of 0. metcalfei than to
any of the other named taxa of the complex.

However, it is not as sharply keeled as is 0. m.
metcalfei and it is more convex (less pyramidal)
dorsally. The surface of confmgom is more
roughly sculptured radially, the distinct sub-
carinal brown spiral band of 0. m. metcalfei is
similar to that of fossil specimens of O. con-
fragosa from Locality 4 but is lacking on adults
from the type locality.

DISCUSSIONS

The 0. metcalfei complex seems to include
the following components (locality numbers and
geographic features mentioned are indicated in
Fig. 1).

(1) In the Black Range and nearby Cuchillo
Mts. occur six subspecies of 0. metcalfei
Cockerell. These are, in addition to the nominal
subspecies, acutidvicu,% concentrica, cnchillensis.
hermosensis and radiata, all described by
Pilsbr>' and Ferriss. One species, 0. pilsbri/i
Ferriss, was also ascribed to the complex bv
Pilsbry (1939:514).

(2) In several isolated mountains to the south
of the Black Range occur fossil or dead,
bleached shells here assigned to OreoheUx
florida Pilsbry. 0. florida is a relatively distinc-
tive member of the 0. metcalfei complex, being
robust, having the highest spire of any member
of the complex, lacking spiral striae and
possessing coarse, radial growth lines. As such,
it seems deserving of specific status. Pilsbry
(1939:513) described 0. metcalfei florida from
the Florida Mts.. Luna County, from old,
bleached shells (ANSP 103243). He also assigned
two fossil shells from the Tres Hermanas Mts.
ra. 25 miles southwest of the Florida Mts. to
this taxon. I have taken one additional fossil
specimen at Locality 6 in the Tres Hermanas
Mts. (MALB 2642). I have also taken fossil
specimens (DMNH 70648; MALB 3634) at
Locality 5 in the Cooke Range, located between
the Florida Mts. and the Black Range. Thus, O.
Jlonda .seems formerly to have penetrated south-
ward at least some 70 miles along these
isolated montane "islands." It is doubtful
whether it is still living in any of them,
however, as the Tres Hermanas Mts. are a low
and arid range and the Cooke Range lacks
limestone in its higher, more mesic parts. Baldy
Peak in the Florida Mts., a high, isolated.

Vol. 88 (4)

THE NAUTILUS

massive limestone outcrop, may have been the
last refuge of the species but collections made
in this century suggest that 0. florida is no
longer living there. In 1970 I found only a few
weathered fragments on the north side of Baldy
Peak (MALE 1201). Pilsbry (1939) did not
illustrate 0. metcalfei florida. Figs. 8 and 10,
herein, show shells from the Tres Hermanas
Mts. and Cooke Range, respectively.

(3) The localities cited herein for 0.
caballoensis extend the range of the 0. met-
calfei complex to the east. This is the only
member known to occur east of the Rio Grande
Valley. It is doubtful that the complex ever ex-
tended any farther east as the next mountain
range eastward, the San Andres Mts., seems, on
the basis of fossils recovered, to have been
inhabited only by 0. socorroe'tms. discussed
below.

(4) Localities of occurrence indicated for 0.
confragosa extend the range of the 0. metcalfei
complex to the west into the Pinos Altos Moun-
tains.

(5) In the Magdalena Mts., some 50-60 miles
north-northeast from the indistinct northern
end of the Black Range, occurs Oreohelix
magdalenae Pilsbry, shells of which, although
slightly smaller, are close to those of 0. m.
cuchillensis and 0. caballoensis. Pilsbry
(1939:515) considered 0. magdalenae to be a
subspecies of 0. socorroensis Pilsbry. This seems
improbable, however, as (a) shells of the two
differ morphologically, with 0. socorroensis
being more depressed, strongly carinate, with
well developed spiral striae and lacking the
brown banding of 0. magdalenae and (b) 0.
socorroensis seems to occur only east of the Rio
Grande Valley, chiefly as a fossil in mountains
surrounding the Tularosa-Hueco Basin (Metcalf
and Johnson, 1971:102-103), whereas 0.
magdalenae seems to occur only in the
Magdalena Mts., west of the Rio Grande Valley.
Probably 0. socorroensis dispersed southward
from a northern source in the 0. yavapai
neomexicana Pilsbry complex, whereas 0.
magdalenae seems more likely a northeastern
derivative of the 0. metcalfei complex.

The 0. metcalfei complex probably has had
its center of dispersal in the relatively large,
high and complex massif of the Black Range

from which it seems to have radiated
propagules in all directions (Fig. 1). Most of the
peripheral kinds (0. magdalenae. 0. caballoensis
and 0. florida along with 0. m. herrnosensis
and 0. m. cuchillensis of the eastern foothills
and adjacent ranges of the Black Range) show
considerable similarity in having elevated,
biconvex shells, in lacking a keel, in possessing
relatively smooth shells lacking spiral striations
and in possession of prominent brown spiral
bands. Kinds of the central Black Range, on the
other hand, exhibit to various degrees
depression and carination of the shell, develop-
ment of elaborate spiral and/or radial striae,
ridges and grooves and the loss of brown band-
ing. 0. confragosa seems closer to the first
(peripheral) group discussed but does possess
fine spiral striae. Brown banding is extremely
weak in living specimens of 0. confragosa but
fossils have better developed bands, suggesting
that evolution towards loss of banding has
taken place.

It seems probable that in the 0. metcalfei
complex shells of the "peripheral group," many
of which are known only as fossils, are more
conservative. Convei-sely, members of the com-
plex inhabiting the Black Range in the highest,
best watered part of the distributional range of
the complex seem to show evidence of a greater
degree of speciation than their more con-
servative, peripheral relatives.

Probably ancestors of the 0. metcalfei com-
plex managed to occupy in one or more
Pleistocene pluvial episodes a number of
mountain ranges in the region, possessing at
that time the shell characters suggested above
as being "conservative." Subsequent desiccation
in one or more interpluvial episodes has
resulted in extinction in some and restriction of
range for other members of the complex.
Peripheral representatives in smaller, lower
mountains have been especially adversely af-
fected. In the Black Range "heartland" of the
complex, however, survival has been more suc-
cessful and speciation has been relatively ac-
celerated.

LIST OF LOCALITIES

1. Sierra Co.; 107° 14' W Long, 32° 56' 13"
N Lat; 6200' elev.; Caballo Mts., from hillslope

100 THE NAUTILUS

October 25. 1974

Vol. 88 (1)

colluvium of Pleistocene age at mouth of
canyon on northwest side of Brushy Mt. This is
a straight box canyon, the first canyon N of
prominent mine on W face of Brushy Mt.. and
debouches near la.st "0" in "6000" elevation
designation on Upham 15' Topo. Quad. A few
specimens were also taken at mouth of a more
tortuously branched canyon, located .65 mi. S,
in colluvium.

2. Sierra Co.; SW'/4.NE'4,SWV4, Sec. 28, T. 16
S. R. 4 W; 5000' elev.; western foothills of
Caballo Mts.. 2 mi. SSE of E end of Caballo
Reservoir Dam, from Pleistocene hillslope
colluvium on steep hillside ca. 100 ft. below
massive limestone rimrock at top of prominent
cuesta east of extensive mining area.

3. Grant Co.; near center of NE'/4, Sec. 12, T.
17 S, R. 12 W; 6700' elev.; Pinos Altos Mts., .3
mi. WSW of west side of ruins of Georgetown
(abandoned mining village) on S (N-facing) wall
of Willow Springs Canyon, below massive
limestone outcrop; snails living under flat
limestone rocks derived from the cliffs above
and strewing the slope; dominant plants on
slope were Junipemt^ monosperma, Pinm eduli^.
Quercus gambelii, Yucca baccata, Garrya
wrightii and Symphoricarpos sp.; collected Sept.
15. 1973.

4. Grant Co.; .45 mi. S of NE comer of Sec.
26. T 17 S, R. 11 W; 6000' elev.; from whitish
hillslope colluvium of Pleistocene age im-
mediately NW of intersection of N.M. Hwy. 90

with paved road leading to Sun Lorenzo and
Mimbres, at base of escarpment flanking Mim-
bres Valley on W side (E side of Pinos Altos
Mts.).

5. Luna Co.; SE'/4,SE'/4.NW'/4. Sec. 24, T. 20
S, R. 9 W; 660(r elev.; Cooke (or Cook) Range;
cuts along road in steep hillside W of and
above abandoned mining village of Cooke (Cook)
at head of prominent NE-draining gulley (with
trail shown on Lake Valley 15' Topo. Quad.) in
central part of village; road cuts in Pleistocene
hillslope colluvium of salient whitish color
(visible several miles away) that contains
fossils.

6. Luna Co.; center, N boundarv of SE' 4. Sec.
26, T. 27 S, R. 9 W; 4.540' elev.; NE part of
Tres Hermanas Mts.. in alluvium exposed in
arroyo bank immediately S of mine that is. in
turn, WSW of Lindy Ann Mine (both shown on
North Peak 7.5' Topo. Quad.).

LITERATURE CITED

Cockerell, T. D. A. 1905. A new (hrohelix.

The Nautilus 18:11.3-114.
Metcalf, A. L. and W. E. Johnson. 1971.

Gastropods of the Franklin Mountains. El

Paso County, Texas. Southwestern Natur.

16:8.5-109.
Pilsbry, H. A. 1939. Land Mollusca of North

America (North of Mexico). Acad. Nat. Sci.

Philadelphia Monogr. l(l):xvii + 573 p.

Vol. 88 (4)

THE NAUTILUS

101

LYMNAEA EMARGINATA. A POSSIBLE AGENT FOR THE CONTROL
OF THE SCHISTOSOME-SNAH. HOST, BIOMPHALARIA GLABRATA'

E. H. Michelson and Lorin DuBois

Department of Tropical Public Health

Harvard Sc'hool of Public Health

665 Huntington Avenue

Boston, Massachusetts 02115

ABSTRACT

Lymnaea emarginata cuntrolled labomtori/ populations of Biomphalaria
glabi-ata by de^troijiny the /offer's C(/,(;-ma,s,sp.s. Previous exposure to B. glabrata
efig-masses accelerated predatioii hij L. emarginata. This phenomenon was con-
sidered to be due to sensitization rather than conditioning, since repeated ex-
posures could not be correlated unth an increase in the efficierwy of preda.tion.
L, emai-ginata was capable of distinguishing between the egg-masses of B.
glabrata and Helisoma caribaeum, and destroyed primarihi those of the former:
however, neither the cyg-iuu.^ses nor their products appeared to attract the
pn (Idtor.

Gastropod mollusks exliibit a greater diversity
of diet and of feeding mechanisms than,
perhaps, any other group of animals (Owen,
1966). However, to our knowledge, there are no
freshwater gastropods which nonnally act as
"true" predators; i.e., actively seek prey. An ex-
ception may be Marisa cornuarietis (Linne) and,
possibly, other members of the Pilidae (Paulinyi
and Paulini, 1972). Chernin et al. (19.56)
demonstrated that M. coniuarietis controlled
Biomphalaria glabrata (Say) populations by
ingesting their egg-masses and newly hatched
snails. They believed this "predation" to be ac-
cidental and due to the Marisa's insatiable ap-
petite for vegetation and its proclivity for con-
tinuous browsing. On the other hand, Demian
and Lutf>' (1965 a & b) reported that Marisa
deliberately preys on young and older snails
and can be "conditioned" to "prefer" a snail
me;d to its normal herbivorous diet. Ob-
sen'ations. in our laboratory, indicated that a
North American pulmonate snail. Liimriaea
cii/argiuata Say, would feed avidly upon the
egg-masses of B. glabrata.

In the present study we asses.sed the ability

of L. emarginata to destroy B. glabrata egg-
masses, the effect of sensitization on the rate of
pi'edation, and determined if this predation

Thes«> studifs were :»iipp<irted in part by Research (ii'ant
.■\I.-lKI.5l:? anil Training Grant A !-()()( U(i from the NIAID.
r.S. Public Health .Service.

DAYS

FICt. 1. Mean shell measurements of Biompha-
laria glabrata populations comprised of 10 B.
glabrata (A). 10 B. glabrata plus 20 L.
emarginata (B), and SO B. glabrata (C). Ex-
periment 5.

in2 THE N'AITILUS

October 25, 1974

Vol. 88 (4)

TABLE 1. Destruction o/B. glabrata eggs by L. emarginata. Twenty snails were used in each trial. Ex-
periment 1.

Trial

Eggs

(masses)

fo eggs destroyed by day:

2 3 4

221

(12)

43.4

84.2

257

(8)

5.1

32.3

191

(6)

34.6

114

(3)

9.6

14.0

39.5

54.4

110

(4)

76.4

95.5

99.1

100

190

(5)

19.5

42.1

78.9

97.9

Snails used in this trial were the same as in trial 4.
'Snails used in this trial were starved for 24 hrs prior to testing.

could, in fact, limit or control the size of B.
glabrata populations.

MATERIALS AND METHODS

A Puerto Rican strain (PR-1) of Biom-
phaknia glabmta (Say), a Virgin Island strain
(CB) of Helisoma Caribaeum (Orb.), and a North
American strain (Michigan) of Lymnaca
emarginata Say were maintained as described
(Michelson, 1966). The snail we call L.
cmanpnata is placed by some workers in the
genus Stagnicola (Inaba, 1969; Burch, 1960 a &
b) and is considered by Walter (1969) to be a
synonym of L. catascojrium Say.

All experiments were conducted in a tem-
perature controlled room (25 ± 1° C). In some
experiments, 6(X) and 1000 ml beakers were
used as aquaria; in others, 3-liter plastic tubs.
Aquaria were filled with equal parts of "con-
ditioned" aquarium water and distilled water,
were exposed to 12 hr of fluorescent light daily,
and for some experiments continuously aerated.
Snails were fed excess amounts of romaine let-
tuce during the experimental period. All snails
were measured with Vernier calipers or an

ocular micrometer (nearest 0.1 mm) and eggs
were examined and counted with the aid of a
stereomicroscope (xl5). Egg-masses were collect-
ed on sheets of plastic-film as described by
Olivier and Haskins (1960). No attempt was
made to match the stage of embr\'onic develop-
ment in the eggs of different masses.

EXPERIMENTAL STUDIES AND RESULTS

Observations on feeding behavior:

B. glabrata egg-masses and individual L.
emanjinata were confined to small Petri dishes
(.50 mm) and observed with the aid of a
stereomicroscope. In most instances, the snail
moved randomly about the dish until an egg-mass
was encountered. An exploratory period followed
in which the snail stroked the mass with its ten-
tacles, occasionally crawled part-way onto the
mass or across it to the opposite side, and finally
adopted a position in which the labial flaps and
mouth were in juxtaposition to the edge of the
mass. Feeding was initiated by the rapid flexing of
the radula and the movement of the jaws. The
snail rasped through the external and egg mem-
branes and then devoured the egg contents and em-
br>'o. No preference was noted for eggs at a par-
ticular stage of development and eggs of all ages
were eaten. Destruction of the mass was not a con-
tinuous process, but occurred at intervals with the

Vol. 88 (4)

THE NAUTILUS

103

TABLE 2. JTie effect of repeated exposure to B. glabrata egg-masses on the ability of L. emarginata to
seek and destroy the eggs of B. glabrata. Experiment 2.

Trials and groups* Eggs (masses)

io eggs destroyed by day:

12 3 4

1, exposed
non-exposed

110
109

(4)
(4)

73.6

33.0

85.5
75.2

98.1
80.7

100.0
90.8

2, exposed
non-exposed

106
104

itJ

17.0

4.8

18.9
4.8

84.0
28.9

100.0
51.9

3. exposed
non-exposed

112
112

100.0
0

0.9

44.6

68.8

4. exposed
non-exposed

68
75

60.3
14.5

72.1
15.8

94.1
28.0

5. exposed
non-exposed

84
81

63.1
29.6

90.5
50.6

100.0
55.6

Mean values
exposed
non-exposed

62.8
16.4

73.4
29.5

95.1
47.6

100.0
82.5

'10 snails were used in each group, and the exposed snails of trial 1 were used as the e.xposed group for each subsequent trial.

snail leaving and then returning after a period of
browsing.

EXPERIMENT 1

Defitniction of B. glabrata eggs by
emarginata in the presence of vegetation.

Small squares of plastic-film, each containing a
single egg-mass, were anchored to the bottoms of
l-liter beakers containing 900 ml of water. Twen-
ty L. emarginata (8.0-11.0 mm in alt.) were in-
troduced into each beaker and an abundant supply
of lettuce added. Efeg-masses were examined daily
for 4 days to determine the number of eggs
destroyed. The data (Table 1) clearly indicates that
L. emarginata preys on B. glabrata eggs, even in
the presence of excess vegetation, and is capable of
destroying 50% or more of the test samples after 4
days. Except in one trial (#5), none of the L.
emarginata had had previous exposure to B.

glabrata egg-masses. This trial suggested that
previous exposure to B. glabrata egg-masses may
"sensitize" L. emarginata to actively seek and
destroy such eggs.

EXPERIMENTS 2 & 3

Effect of pre-exposure on the rate ofpredation.

The following experiments were designed to test
the hypothesis that L. emarginata pre-exposed to
B. glabrata egg-masses became sensitized and thus
destroyed egg-masses more rapidly than non-
exposed snails. A group of 10 snails were exposed
for 4 days to B. glabrata egg-masses. The same
group of "exposed" snails were then used in 6 con-
.secutive trials and their predatory activity com-
pared with groups of non-exposed snails. Trials of
"exposed" and "non-exposed" snails were run
simultaneously in 1-liter beakers containing 900
ml of water and an abundance of lettuce.

ini THE NAUTILUS

October 25, 1974

Vol. 88 (1)

TABLE 3. The effect of previous exposure to B. glabrata egg-masses on the ability of L. emarginata to
seek and destroy the eggs of B. glabrata. Experiment 3.

Trials and groups*

Eggs''

% eggs destroyed, on day 1:

1, exposed
non-exposed

2, exposed
non-exposed

3, exposed
non-exposed

4« exposed

non-exposed

5. exposed
non-exposed

6. exposed

non-exposed

7. exposed
non-exposed

8. exposed
non-exposed

101
100

100
97

96
103

101
100

99
102

98
103

100
100

63.4
4.0

31.0
3.1

30.2
1.0

9.9
30.0

18.8
0

10.1
0

22.5
2.9

0
0

*5 snails were used in each group per trial.

+ 8 egg-masses were used for each group in all trials.

Results (Table 2) appear to indicate that "ex-
posed" snails find and destroy egg-masses more
quickly than do "non-exposed" snails. Since it was
possible that the snails of the "exposed" group
were in some manner atypical, another ex-
periment was set up to overcome this contingency.
In this experiment (#3), 8 groups of pre-exposed
snails were compared with similar groups of non-
exposed snails. F]ach group consisted of 5 L.
emarginata (7.0-9.5 mm in alt.) and the trials were
conducted in 600 ml beakers filled with 500 ml of
water and a supply of lettuce.

The results (Table 3) clearly support the
premise that pre-exposure to B. glabrata eggs in-
creased the rate of destruction of such eggs by L.
emarginata. The rate of egg destruction by "ex-

posed" snails was found to be significantly greater
than that of "non-exposed" snails when the data
was analyzed by the Wilcoxsin rank test for un-
paired measurements: p = 0.02.
EXPERIMENT 4

Selectivity of L. emarginata ./"or planorhid egg-
masses.

This experiment was designed to determine if L.
emarginata was selective in its choice of egg-
masses or would attack any planorbid egg-masses.
Trials were set up as in Rxperiments 2 and 3, but
used either H. caribaeum egg-masses or a mixture
of H. c(tribacHm and B. glabrata masses. Results
are summarized in Table 4 and indicate that L.
emarginata preys only to a limited extent on the
eggs of H. caribaeum. Moreover, when both tyjies
of egg-ma.sses were presented simultaneously, only
those of B. glabrata were eaten.

Vol. 88 (4) THE NAUTILUS 105

TABLE 4. Faiiiin' ofL. emarginata to dcMroii Helisoma caribaeum ('g(i-ma.<;<!f's. Kriicriincnf .',.

Trial*
and Egg
type

Eggs

(masses)

% eggs destroyed by day:
12 3 4

1.
2.

3.
4.
5.
6.

H. caribaeum

caribaeum

and
glabrata

caribaeum

and
glabrata

46
46
41
53
94
88

50
53
53
52

(3)

(4)

(10)

(8)

(4)

(3)

1.9

3.2

6.8

9.4

34.0

50.9

64.2

1.0

1.9

5.4

19.2

21.2

23.1

"S snails were used in trials 1 + 2, 5 in trials 3 + 4. and 10 in all others.
+ In these trials both t\T3es of egg-masses were placed in the same beaker.

EXPERIMENTS 5 & 6

Cdutriil (if B. glabrata populatinns by L.
emarginata.

The following series of experiments explore
whether or not the predation exercised by L.
( itKuyimita is sufficient to limit the growth of
B. (jlabmta populations. Two 3-liter aquaria
were set up so that "A" contained only 10 B.
glabirita (mean diam. = 7.8 mm) and "B" con-
tained 10 B. glabrata (mean diam. = 7.8 mm)
plus 20 L. emarginata (mean alt. = 11.8 mm).
Snails of both species were approaching sexual
maturity at the onset of the experiment, and
eggs deposited by both species w'ere permitted
to hatch. The experiment ran for 6 wks, at
which time all snails and egg-masses were iden-
tified and counted.

The results of- the experiment w'ere as
follows: 1) aquarium "A" contained, in addition

to the original 10 snails, 1225 new- B. glabrata
and 59 egg-masses; 2) aquarium "B" contained
10 and 16 respectively of the original snails,
190 new B. glabrata, 244 new L. emarginata, 4
B. glabrata egg-masses, and 8 L. emarginata
egg-masses. Thus, in the presence of L.
emarginata, B. glabrata increased only 19-fold
as compared to a 122.5-fold in the control
aquarium. In a replicate experiment, the B.
glabrata population increased 11.5-fold in the
mixed-species aquarium, whereas, the controls
showed a 99.8 fold-increase.

The previous experiment failed to rule out
the possibility that the slower rate of growth of
the B. glabrata population in the mixed-species
aquarium was related as much to "crowding"
by L. emarginata as to predation. Experiment
6, therefore, was designed to determine if the
"crowding phenomenon" (i.e., concomitant reduc-
tion in growth and fecundity) observed in

106 THE NAUTILUS

October 25. 1974

Vol. 88 (4)

TABLE 5. TTie effect ofL. emarginata on the fecundity of a population of B. glabrata. Summary of ob-
servations over a period of 9 weeks. Experiment 6.

Criteria of

Fecundity

of Populations

fecundity °

B. glabr
(A)

ata

10
20

glabrata +
emarginata

(B)

B, glabrata

(c)

Total egg-masses

193

llo

323

Total eggs*

4509

3098

5572

Mean eggs/snail

459.4

322.7

186.4

'In populations A and C, egg deposition began during the 3rd week of the experiment; in B during the 4th week.
Based on mean number of surviving snails per week.

crowded mono-specific populations of pulmonale
snails (Chernin and Michelson, 1957;
Szumelwicz, 19.58; Wright, 1960; Shiff, 1964;
Jobin and Michelson, 1969; Sturrock and
Sturrock, 1970) would also operate in mixed-
species populations. Accordingly, three 3-liter
aquaria were set up as follows: "A" with 10 B.
glabrata, "B" with 10 B. glabrata and 20 L.
emntr/inata and "C" with 30 B. glabrata. The
experiment ran for 9 weeks and was replicated
twice. Egg-masses were removed weekly and
eggs counted.

The results indicate that L. emarginata did
not exert a "crowding effect" on the B. glabrata
population with respect to growth (compare A
and B in Fig. 1). However, the differences be-
tween the means of populations A and C were
highly significant when analyzed by the students
"t" test; p = < .01. Egg production (per
snail) of the isolated B. glabrata populations
was, as expected, greater in the less crowded
aquarium ("A") than in the more crowded
aquarium ("C"); however, fecundity was lower
than expected in "B" considering that the
growth of the B. glabrata population was not
inhibited by the presence of L. emargiiuita
(Table 5). Replicate experiments gave essentially
the same results.

MISCELLANEOUS EXPERIMENTS

Efforts to di^uise the egg-masses of B.
glabrata by immersing them, for 1 hr. in an ex-
tract prepared from L. tniarginata egg-masses
failed to protect them from predation.

To determine if a chemo-attractive substance
was released by egg-masses of B. glabrata. we
employed a plastic maze (Michelson, 19<i(l) and
used as bait either intact egg-masses, punctured
egg-masses, or filter paper discs impregnated
with egg extracts. Eiich bait was tested in 21
individual trials and employed a new snail (7.0-
9.0 mm) for each trial. No evidence of a
chemo-attractive response was elicited from L.
emarginata.

DISCUSSION

Our data indicate that Lymnaea cmaniiiiata
was effective in controlling laboratory
populations of Binmphalaria glabrata. Control
appeared to be exercised as a result of egg
destruction, and was not associated with a reduc-
tion of fecundit\' imposed by crowding.
Although previous exposure to B. glabrata egg-
mas.ses appears to enhance L. emarginata'ft
ability to destroy eggs, "conditioning", in the
sense that repeated exposures can be directly

Vol. 88 (4)

THE NAUTILUS

107

correlated with an increase in effectiveness, has
not been demonstrated. Our observations sup-
port the studies of Wells and Wells (1971) and
of Cook (1971) that pulmonate snails can be
sensitized, but are incapable of being con-
ditioned. L. emarginata appeared to be able to
differentiate between H. cnrihaeum and B.
glabrata egg-masses, attacking only tho.se of the
latter. However, we could detect no chemo-
attractant emitted from the egg-masses of B.
glabrata. and recognition may be tactile. In
nature, L. emarginata and species of Helisoma
occur together; whereas, species of Biomphalaria
are restricted geographically to the tropics and
sub-tropics. One might speculate, therefore, that
the predation of B. glabrata egg-masses is an
adaptive mechanism by which L. emarginata
limits potential competitors.

L. emarginata appears to be restricted to the
Northern Temperate Region of North America
and has been found rarely below 40° North
Latitude (LaRocque, 1968; van der Schalie and
Berry, 1973). Recently, van der Schalie and
Berry (1973) have shown that this species, in
the laboratory, has optimal longevity and
reproductive potential at temperatures ranging
from 22° -26° C; at temperatures approaching
30° C, marked mortality occurs. It should be
noted, however, that contrary to popular belief,
many aquatic habitats in the Tropics rarely
have temperatures which regularlv e.xceed
28 C (Jobin, 1970).

Although L. emarginata could be reared at
tropical temperatures in the laboratory and
showed no evidence of stress, there is no in-
dication that the control exercised by this snail
in the laboratory could occur under natural
conditions. In fact, the ability of L. emarginata
to serve as a host for non-human schistosomes
(McMullen and Beaver, 1945) may preclude its
use as a control agent. Nonetheless, in this era
of environmental sensitivity, alternatives to
molluscicides warrant further attention.

LITERATURE CITED

Burch, J. B., 1960a. Chromosome morphology of
aquatic pulmonate snails (Mollusca:
Pulmonata). Trans. Amer. Microscop. Soc,
79:451-461.

Burch, J. B., 1960b. Chromosome studies of

aquatic pulmonate snails. The Nucleus,
3:177-208.

Chernin, E., E. H. Michelson, and D. L.
Augustine, 1956. Studies on the biological
control of schistosome-bearing snails. I. The
control of Australorbis glabratux populations
by the snail, Marim cornuarieti.'i. under lab-
oratory conditions. Amer. Jour. Trop. Med.
Hyg., 5:297-307.

Chernin, E., and E. H. Michelson, 1957. Studies
on the biological control of schistosome-
bearing snails. III. The effects of population
density on growth and fecundity in Austra-
lorbis glabratus. Amer. Jour. Hyg., 65:57-70.

Cook, A., 1971. Habituation in a freshwater
snail (Limnaea t^tagnaiui). Anim. Behav.,
19:463-474.

Demian, E. S., and R. G. Lutfy, 1965a. Preda-
toi-y activity of Marisa cornuarietis against
Bulinus (Bulinus) truncatus. the transmitter
of urinary schistosomiasis. Ann. Trop. Med.
Parasit. 59:331-336.

Demian, E. S., and R. G. Lutfy, 1965b. Factors
affecting the predation of Marisa romuarietis
on Bulinus (B.) truncatus, Biomphalaria
alexandrina and Lymnaea caillaudi Oikos,
17:212-230.

Inaba, A., 1969. Cytotaxonomic studies of
lymnaeid snails. Malacologia, 7:143-168.

Jobin, W. R., and E. H. Michelson, 1969.
Operation of irrigation reservoirs for the
control of snails. Amer. Jour. Trop. Med.
Hyg., 18:297-304.

Jobin, W. R., 1970. Population dynamics of
aquatic snails in three farm ponds of Puerto
Rico. Amer. Jour. Trop. Med. Hyg., 19:1038-
1048.

LaRocque, A., 1968. Pleistocene Mollusca of
Ohio. Geological Surv. Ohio, Bull, 62. Pt.
3, pp. 357-553.

McMullen, D. B., and P. C. Beaver, 1945.
Studies on schistosome dermatitis. IX. The life
cycles of three dermatitis-producing schisto-
somes from birds and a discussion of the sub-
family Bilharziellae (Trematoda: Schisto-
somatidae). Amer. Jour. Hyg., 42:128-154.

Michelson, E. H., 1957. Studies on the biological
control of schistosome-bearing snails. Predators
and parasites of freshwater Mollusca: A review
of the literature. Parasitology, 47:413-426.

108 THE NAUTILUS

October 25, 197

Vol. 88 (J)

Michelson, E. H.. 1960, Chemoreception in the
snail Auatralorbis glabratus. Amer. Jour.
Trop. Med. Hyg.. 9:480-487.

Michelson, E. H., 1966. Specificity of hemo-
lymph antigens in taxonomic discrimination
ot medically important snails. Jour. Parasit.,
52:166-472.

Oliver-Gonzalez, J., P. M. Bauman, and A. S.
Benenson, 1956. E^ffect of the snail Marim
ciirnnarietis on A>i><trrilnrbis glabratuti in
natural bodies of water in Puerto Rico.
Amer. Jour. Trop. Med. Hyg., 5:290-296.

Oliver-Gonzalez, J., and F. F. Ferguson, 1959.
Probable biological control of Schistosomiasis
niansom in a Puerto Rican watershed. Amer.
Jour. Ti-op. Med. Hyg., 8:5(;-:)9.

Olivier, L.. and W. T. Haskins, 1960. The
effects of low concentrations of sodium penta-
chlorophenate on the fecundity and egg
viability of Australorbis glabratus. Amer.
Jour. Trop. Med. Hyg., 9:199-205.

Owen, G., 1966. Feeding. Chapt. I in Physioloyn
of Molluscs ed. K. M. Wilbur and C. M.
Yonge, vol. II, Academic Press, New York
and London.

Paulinyi, H. M., and E. Paulini, 1972. Labora-
tory observations on the biological control of
Biomphalnria glabrata by 2 species of
Pomncea (Ampullariidae). Bull, World Health
Org.. 46:243-247.

Radke, M. G., L. S. Ritchie, and F. F.

Ferguson, 1961. D monstrated control of
Australorbis glabratus by Marisa cornuarietis
under field conditions in Puerto Rico. Amer.
Jour. Trop. Med. Hyg., 10:370-373.

Shiff. C. J., 1964. Studies on Bulinus
(Physo'psis) globosus in Rhodesia. II. Fac'ir
influencing the relationship between rate and
growth. Ann. Trop. Med. Parasit., 58:106-115.

Sturrock, R. F., and B. M. Sturrock, 1970.
Observations on some factors affecting the
growth rate and fecundity of Biomphalnria
glabrata. Ann. Trop. Med. Parasit., 64:349-
355.

Szumlewicz, A. P.. 1958. Studies on the biology
of Australorbis glabratus. schistosome-bearing
Brazilian snail. Rev. Mai. e. Douncas Trop.,
9:495-529.

Van der Schalie, H., and E. G. Berry 1973. The
effects of temperature on growth and repro-
duction of aquatic snails. Sterkiana, No. 50,
92 pp.

Walter, H. J., 19(i9. Illustrated biomoi-phology
of the 'Augnlota" like form of the basomma-
tophoren snail Liimyiaea catascnpinm Say.
Malacological Review, 2:1-102.

Wells, M. J., and J. Wells, 1971. Conditioning
and sensitizaMon in snails. Anim. Hehav.,
19:305-312.

Wright, C. A., 19* ftie crowding phenomenon
in laboratory c inies of freshwater snails.
Ann. Trop. Ml-' ^'arasit.. 54:221-232.

BOOK REVIEW

DICIONARIO CONQUILIO e MALACOLOGKU
Bg Maury Pinto dc Oliveira and Maria
Helena Rodriques de Oliveira. 197i. 190
pp. Mimsterio da Educa^ao. Univ. Fcdrnd
Juiz de Fora, Miims Gerais, Brazil. Paper-
back.

Tliis handy dictionary and glossary of con-
chological and anatomical terms will serve
well those who consult the Portuguese litera-
ture of mollusks. Also included are the Portu-
guese names for various geographical regions. —
A'. Tuvkcr Ahhott.

Vol. 88 (1)

THE NAUTILUS

109

DEVELOPMENT OF BROOD SACS IN MUSCULIUM
SECURIS BIVALVIA: SPHAERIIDAE

G. L. Mackie', S. U. Qadri and A. H. Clarke"

Biology Department, University of Ottawa
Ottawa, Ontario, Canada

ABSTRACT

In Musculiuni securis (Prime) brood .sar.s develop from and remain associated
with certain filaments of the inner gill. Brood sacs do not migrate along
the filamenU as reported in the literature for other species of Sphaeriidae,
but remain stationary. The brood sacfilament relationship enables detennina-
tions of the numbers of litters produced by back-calculation of brood sacs.

INTRODUCTION

Sphaeriids are ovoviviparous with the ferti-
lized egg developing in brood sacs on the inner
gill of the parent until the young are mature
enough to be released to the outside. Okada
(1935) and Gilmore (1917) have described the
structure and development of three types of
brood sacs (primary, secondary, and tertiary)
which occur during larval development of
sphaeriids. The development of brood sacs in
M. secmis is markedly different from descrip-
tions in the literature of other sphaeriids but
the structure appears to be similar. The pre-
sent paper reports these differences and des-
cribes the significance of brood sac development
in life history studies.

MATERIALS AND METHODS

Four populations of M. securis were studied.
Two populations were from temporary forest
ponds, one from a permanent pond, and the
fourth from a river bed. All habitats are within
a 45 km radius of Ottaw-a, Ontario, and are
described by Mackie (1973). Samples of 30-100
clams were removed from each habitat usually
at two week intervals during the summer and
one month intervals during the winter. Each
specimen was isolated and preserved in a two
dram vial containing HT/n ethanol.

The shell length (anterior to posterior) of
each adult was measured to two decimal

OOBSOANTEBIOR Fnr.r qf

'Present address: Department of Zoology, Universit.\- of
Guelph. Guelph. Ontario. Canada.

- Present address; National Museum of Natural Sciences,
National Museums of Canada. Ottawa, Ontario. Canada.

FIG. 1. Position of the brood sacs and their
relation to the gill filaments of the inner gill.
DF: degenerating filaments. DPS: developing
primary sac. E: embryo. FL: fetal larvae.
IG inner gill, OG outer gill PGF gill fila-
ments supporting primary sac. PL: prodis-
soconch larvae. PS: primary sac. SGF: gill fila-
ments supporiing secondary sac: SS secondary
sac. TGF: gill filaments supporting tertiary
sac. See text for explanation of a, b. c. d e.
and f

places in millimeters with a Precision Tool
and Instrument Co., Ltd. microscope micro-
meter, model 14. The left and right inner gills

110 THE NAUTILUS

October 25, 1971

Vol. 88 (4)

£ 6
E

2 5H

UJ
01

I/)
<

2 4

u
<

§3

O
cc

z 2
<

Height a- f

Height a-c

Height Q-b

LENGTH OF

FIG. 2. Growth of the inner gill and various
aspects of the first and second brood sacs in
relation to growth in shell length of parenbi
of Musculium securis. See text and Fig. 10
for explanation of af. a-b, e-f and df.

were excised from each parent and the brood
sacfilament relationship was determined in the
following manner. Filaments were numbered
consecutively beginning at the dorso-anterior
edge of the gill (Fig. 1). Brood sacs were des-
ignated as first, second, third, or fourth, depen-
ding on the sequence in which they developed.
Data was recorded to show which brood sac
was associated with which filaments in each
parent.

In addition, several measurements were taken
to determine the relationship between the
growth in height of inner gills and brood sacs
and the growth in .shell length of parents.
Referring to Fig. 1, the total height of the gill
(a-f) and the height of brood sacs (b-d and
c-e), were measured in parents of several ages.
Only the first two sacs were measured because

PARENT

— r-
5

Height e-f
Heiijiht d-f

M. securis usually produces only two litters
(Mackie, 1973). The lengths a-b, a-c and d-f.
e-f are measures of growth of first and second
brood sacs in the dorsal and ventral directions,
respectively.

There were no significant differences (P>fl.05)
in the brood sacfilament relationship nor in the
relationship between the growth of gills and
brood sacs and the growth of parents among
populations. Therefore, clams from each habitat
were combined and treated as a sample popu-
lation.

RESULTS
In M. securis the brood sacs are associated
with certain filaments of the inner gill (Fig. 1).
Of an estimated 10,000 brood sacs examined,
all develop from either two or three gill fila-
ments. Counting down from the dorso-anterior
edge of the gill (Fig. 1), the first sac usually
develops on the 7th and 8th gill filaments, the
second on the 9th and 10th, the third on the
11th and r2th, and the fourth on the i;3th and

Vol. 88 (4)

THE NAUTILUS

111

14th gill filaments. Each sac remains associated
with the filaments from which it arises until
the sac ruptures, releasing the enclcsed pro-
dissoconch larvae. Occasionally brood sacs de-
velop from three filaments so that the first
sac is on filaments 7, 8, 9, the second on 10, 11,
the third on 12, 13, and the fourth on 14, 15,
16 or the first is on 7, 8, and the second on
9, 10, 11, the third on 12, 13, and the fourth on
14, 15, 16. Nearly all combinations of gill fila-
ments occur e.xcept two adjacent sacs each co-
cupying three filaments.

Measurements of 150 parents showed that the
growth of brood sacs and gills are directly
related to the growth of parents (Fig. 2).
Also the growth of brood sacs is linearly re-
lated to the growth of gills (Fig. 2). The dis-
tance between the dorsal edge of the gill
(a. Fig. 1) and the dorsal edge of the first
sac (b. Fig. 1) decreases with increasing age
of the parent, indicating that the sac advances
dorsally (Fig. 2). However, the distance between
the ventral edge of the first sac (d, Fig 1)
and the ventral edge of the gill (f. Fig. 1)
remain constant and is exactly one half
the length of the gill in all parents (Fig. 2).
Since the gill grows in a ventral direction
(Raven, 1958), the brood sacs must advance
in the ventral direction at an identical rate.

DISCUSSION

Okada (1935) does not associate the brood
sacs with gill filaments in M. heterodon but
maintains that "the sac moves upwards along
the descending lamella" by formation and re-
formation of new sac stalks. This does not
occur in M. securis since the ventral edge of
the sacs advance ventrally (i.e. dowTiwards)
at an identical rate of the growth of gills. More-
over, there is no evidence of the sac stalks
forming and reforming since the sacs are
always attached dorsally and ventrally to the
gill filaments. Okada (1935b) also states that
the sacs move from "the lower part to the upper
part of the branchial chamber". This cannot
occur in M. securis because the sacs remain
attached to the filaments from which they
arise. Rather, the sacs merely enlarge with
the growth of the enclosed larv^ae.

Since brood sacs are associated with certain
gill filaments, the numbers of litters produced

by a parent can be determined by back cal-
culation of brood .sacs. Thus, parents that have
produced one litter will not have brood sacs
on filament numbers 7 and 8, but will have
brood sacs on filaments 9-14, 9-15, or 9-16.
Similarly, parents that have produced two lit-
ters will not have brood sacs on filament num-
bers 7 and 8 nor on 9 and 10. This technique
can be applied to parents in which brood sacs
develop from two filaments. For parents in
which brood sacs develop from three filaments,
two litters were produced if filament numbers
7, 8, 9, 10. 11 have no brood sacs (we have
never seen the 12th filament used in the for-
mation of the second brood sac), three litters
if filament number 7-13 inclusive (or 7-14
inclusive) have no brood sacs. Usually sac
remnants remain to determine whether a sac
has developed from two or three filaments. Lf no
sac remnants are present, one only needs to refer
to filament numbers 8, 10, and 12, since they are
always present in the formation of the first, second
and thrid brood sacs, respectively, regalrdless of
the number of filaments used in sac development.
If indeed the 12th filament is used in the develop-
ment of the second brood sac, errors would be
introduced into the estimation of the third and
fourth litters. This is particularly true if sac rem-
nants are not present to determine the number of
filaments used in sac development.

ACKNO WLEDGEM ENTS
The research was supported by the National

Research Council of Canada, Grant No. A

2386 awarded to S. U. Qadri.

LITERATURE CITED

Gilmore, R. J. 1917. Notes on reproduction and
growth in certain viviparous mussels of the
family Sphaeriidae. The Nautilus 31: 16-30.

Mackie, G. L. 1973. Biology of Musculmm
securis (Pelecypoda: Sphaeriidae) in two
temporary forest ponds, a river, and a perm-
anent pond near Ottawa, Canada. PhD dis-
sertation, University of Ottawa, Ottawa. 175p.

Okada, K. 1935. Some notes on Musculium hetero-
don (Pilsbry), a freshwater bivalve. II. The gill,
breeding habits and marsupial sac. Sac. Rpt.
Tohoku Imp. Univ. Ser. 4, Biol. 9: 375-391.

Raven, C. P. 1958. Morphogenesis: the analysis
of molluscan development. Pergamon Press, New
York. 311 p.

11-2 THE NAUTILUS

October 25. 1974

DESTRUCTION OF KELP PCjI'ULA^'ONS
BY LACUNA VINCTA (MONTAGU)

Richard A. Fralick. Kenneth W. Turgeon and Arthur C. Mathieson

JacLson Estuarine kibn'atury

University of New Hampshire, Adams Point

New Hampshire 03824

Vol. 88 (4)

1,2

ABSTRACT

,4 localized po/julation expansion of Lacuna vincta (MuntayiiJ
has caused a marked depletion of kelp populations near Newcastle Island,
New Hampshire. .4.s many as 277 snails per Laminaria plant were observed.
Tfie stipes and blades of Laminaria plants become riddled with holes (up
to 12 holes/25 cm^) from L. vincta; eventually only residual holdfasts and
stipes remain. A grazing rate of 0..i26 cm- of Laminaria saccharina blades/
snail/day was recorded in the laboratory. Respiration studies indicate that
L. vincta is an osmoconforming species with a salinity optimum of about
25 %o. It is suggested that the popndation increase of L. vincta may have been
initiated after a period of extensive rainfall, - i.e. reduced salinities. Lacuna
vincta may be a major grazer of seaweeds in a variety of locations.

WTiile conducting subtidal studies of the benthic
marine algae of New Hampshire we have
observed extensive grazing of Laminaria
populations by the prosobranch gastropod.
Lacuna vincta (Montagu). The gastropod is a
small (L0-L5 mm wide and L0-L8 mm long) lit-
torinid snail (Fig. 1) that is often found in
limited numbers on kelps and other seaweeds
along the northeast coast of North America
(Miner. 1950). During 1972 we have obsen'ed a
"population e.xplosion" of L. vincta at Newcastle
Island. New Hampshire (43° 04' 05" Latitude
and 70 ° 42' 45" Longitude), and a marked
depletion of in situ kelp beds. Subsequently we
have seen continued destruction of kelp
populations at Newcastle Island, as well as at
adjoining open coastal and estuarine sites in
Southern Maine and New Hampshire.

In June, 1972, we examined 64 randomly
collected specimens of Laminaria saccharina
and L. digitata within a 100(.) m" area at
Newcastle Island at 3 to 6 m below mean low
water. All of the plants exhibited severe
damage, for their fronds and stipes were rid-
dled with round or ellipsoidal holes that were

;3-10 mm in diameter (Fig. 2 and 3). As many
as 12 holes per 25 cm' were found on many
blades. The majority of the holes penetrated
through the entire plant(s). In most cases the
blades were more heavily grazed than other
portions of the plants. The intercalary
meristem, or the transitional zone between the
blade and stipe, was rarely damaged. At sites
with heavy grazing only residual holdfasts and
stipes of Laminaria were present.

During July, 1972 we found as many as 277

FIG. 1. Two New Hampshire specimens of
Lacuna vincta (Montagu). 30 X.

Published as .Jackson Estuarine Lab<iratory Scientific
Contribution Number 2.

Published with the approval of the Director of the New
Hampshire .Agricultural Experiment Station as Scientific
G)ntribution Number (iTT ■

Vol. SS (1)

THE NAUTILUS

U:]

snails per Laminai'ia saccharina plant at
Newcastle Island - at 3 to 6 m below mean low
water. In the early part of the summer few
snails were fovmd on the understory vegetation
beneath the kelp canopy. However, as the sum-
mer progressed a variety of economically im-
portant species such as Chondru^ fr/,s'p(;,s, Gigar-
tina stellata and Rhodymenia palmata
(Mathieson, 1969) also showed extensive grazing
by Lacuna vincta.

Kain (1971) and R. Waaland (personal com-
munication to A.M.) also report abundant
populations of L. vincta on seaweeds in Norway
and Washington, U.S.A., respectively. Thus,
Lacuna may be a major grazer of seaweeds in a
variety of locations. Kain and Svendsen (1969)
record e.xtensive grazing by the gastropod
Patina pellucida on Laminaria hyperborea in
western Norway and Great Britain: they state
that P. pellucida may cause considerable loss of
plants due to weakening of the holdfast or
damage to the frond or stipe. In Great Britain
they observed that the animals initially settled
on the frond and then migrated to the holdfast,
where they created large cavities. Preliminary

observations indicate that L. vincta may show a
similar pattern of attachment and migration on
New England kelps. According to Kain (1971)
0. Vahl (unpublished daUi) has found con-
siderably higher densities of L. vincta than P.
pellucida on Laminaria hijpcrborpa populations
in Norway, and the holes it makes are much
deepei' than those of P. pellucida.

Preliminary culture e.xperiments were con-
ducted in August and September, 1972, in order
to determine grazing rates of L. vincta on
Laminaria sacchaiina. A small section of
frond (25 cm") was p'aced in a crystallizing
dish with 200 ml of filtered sea water (30 %.)
and 10 snails. The dishes were incubated at
300-400 foot-candles and at 10° C in a Sherer-
Gillete Incubator. After 5 days the fronds were
remeasured and the consumption of plant mate-
rial was determined. An average grazing rate of
0.326 cm'-'snail/day was recorded. It should be
emphasized that this is an approximation and
further studies should be conducted to deter-
mine the effects of differential temperatures,
salinities and plant materials on grazing.

Respiration rates of L. vincta at IOC and in
three different salinities (20, 25, and 30 %, )
were measured in a Gilson Differential
Respirometer (Model GRP-14), according to the
methods outlined by Mathieson and Burns
(1971). The temperature was maintained at
about 0.1 C; it was the same as the ambient
temperature when the snails were collected.
Two flasks containing ten snails per flask were
run at each of the test salinities. The
respiration rates for the three salinities were
recorded simultaneously in the same in-
strument. Figure 4 illustrates the results of the

i !</<

FIG. 2. A Laminaria saccharina plant showing
severe damage from L. vincta.

FIG. 3. A stipe of Laminaria saccharina
riddled by L. vincta.

114 THE NAUTILUS

October 25, 1974

Vol. 88 (4)

150'

t—

E
O

100'

50'

20 25

SALINITY (%o)

FIG. 4. Respiration of L. vincta at lOC and
in three different salinities.

experiment. The lowest respiration rates were
found at 20 %« and the highest was recorded
at 25 %o . The results suggest that L. viwta is
an osmoconforming species with a salinity op-
timum of about 25 %o.

In conclusion the extensive grazing of
seaweeds at Newcastle Island, New Hampshire,
appears to be directly associated with a
localized population expansion of L. vincta. Our
laboratory studies confirm the field observations
that L. vincta was the causative organism. It
should be emphasized that previous seasonal in-
vestigations at Newcastle Island (Mathieson, et
ai. in press) have never shown extensive
seaweed grazing by L. vincta It is suggested
that the population increase of Lacuna may
have been associated with a spring season

(1972) with abnormally high rainfall, and thus
periods of reduced salinities. Our respiration
studies confirm the tolerance of L. vincta to
low salinity regimes recorded prior to the
period of severe grazing. It is apparent that
further studies of gastropod/algal grazing
should be conducted in the New England area.

ACKNO WLEDGEM ENTS

We would like to thank Dr. R. D. Turner.
Museum of Comparative Zoology, Han'ard
University and Dr. R. T. Abbott, Delaware
Museum of Natural History, for confirming
the identification of Lacuna vincta and en-
couraging our study of its grazing on seaweeds.

LITERATURE CITED

Kain, J. M. 1971. Synopsis of biological data on
Laminaiia hypeborea, FAO, United Nations,
Fisheries Synopsis no. 87, 63 pp, Rome.

Kain, J. M. and P. Svendsen. 1969. A note
on the behavior of Patina pellacida in Bri-
tain and Norway. Sarsia 38: 25-30.

Mathieson, A. C. 1969. The promise of seaweeds.
Oceanology International Jan./Feb., pp 37-39.

Mathieson, A. C. and R. L. Bums. 1971. Ecology
of economic red algae. I. Photosynthesis
and respiration of Chondnis crispus Stack-
house and Oigartina stellata (Stackhouse)
Batters. J. Exp. Mar. Biol. Ecol. 7: 197-206.

Mathieson, A. C, E. Hehre and N. B. Reynolds.
Investigations of New England marine algae
I. A floristic and descriptive ecological study
of the marine algae at Jaffrey Point, New
Hampshire. Nova Hedwigia (in press).

Miner, R. W. 1950. Field book of seashore
life. G. P. Putnam's Sons, New York, 888 pp.

Vol. 88 (4)

THE NAUTILUS

115

ROLE OF THE INCURRENT SIPHONAL VALVE IN THE SURF CLAM.
SPISULA SOLIDISSIMA (MACTRIDAE)

David J. Prior

School of Biological Sciences

University of Kentucky
Lexington, Kentucky 40506

ABSTRACT

Observations of the behavior of the surf clam, Spisula solidissima have indicated
that debris such as sand may be entrapped in the incurrent siphon cavity temporarily
before being expelled by a jet of ivater from the mantle cavity. Vie morphology
and responses of the incurrent siphonal valve are well suited for mediation of a pos-
sible sand storage behavior. The incurrent siphonal valve is positioned across the
opening between the incurrent siphon cavity and the mantle cavity, hence can. when
extended, separate the two caiitie.s. Extetmon (closing) of the valve occurs in response
to mild tactile stimulation of the siphons. Contraction (opening) of the valve only
occurs in response to strong tactile stimtdation. The responses of the incurrent si-
phonal valve and the adductor muscles (which cause the jet of ivater) are co-ordinated
in such a way that during the cleaning reflex the valve is open when shell valve
adduction occurs thus allowing free passage of water out of the mantle cavity.

While studying the neural control of siphon
withdrawal in the surf clam, Spisula solidissima
(Dillwyn), it was necessary to examine siphonal
behavior in detail, (Prior, 1972).

The siphons of Spisula respond in a
progressively more complex fashion as the in-
tensity of tactile stimulation of the siphonal
tentacles (papillae) is increased. In response to
touching a single siphonal tentacle with a glass
stylus the siphon apertures close (a local reflex
mediated by peripherally located neurons). As
the intensity of tactile stimulation is increased
(touching several tentacles or the inner wall of
the incurrent siphon) the siphon musculature
responds with progressively greater contractions
until finally, the siphon retractor muscles
respond, withdrawing the siphons into the man-
tle cavity.

Often in response to gentle tactile
stimulation, such as touching several tentacles,
siphon closure is rapidly followed by con-
traction of the adductor muscles, which by
drawing the shell valves together, cause the ex-
pulsion of a jet of water out the incurrent
siphon (the excurrent siphon remains closed).
This "Cleaning reflex" occurs regularly and

serves to eliminate feces and debris, such as
sand, drawn in through the incurrent siphon.

In one of the very few reports on ob-
servations of Spisula in their natural habitat,
Jacobson (1972) describes the siphonal behavior
of young individuals in a sandy intertidal zone.
During the intei-wave periods the clams kept
their siphons open. But in response to each
sand laden wave, the siphons were observed to
close rapidly. The siphons remained closed until
the sand settled and was no longer being roiled
about. Jacobson further noted that at somewhat
regular intervals a small jet of water, laden
with sand grains, was ejected from the in-
current siphon (the cleaning reflex). Jacobson
points out that this cleaning reflex is of adap-
tive value in that it minimizes the build up of
sand in the mantle cavity. Furthermore, he
suggests that sand is probably stored briefly in
the incurrent siphon before being expelled, as a
further means of preventing accumulation in
the mantle cavity.

The present report describes the anatomy and
general responses of a muscular flap of tissue
(incurrent siphonal valve) in Spisula that is
positioned across the opening of the incurrent

116 THE NAUTILUS

October 25, 1974

Vol. 88 (4)

SRM

FIG. 1. .4 schematic of the posterior end of a
clitni with the incurrent siphon (IS) and
excinrtnt siphon (ES) in an extended positian.
One of the siphon retractor muscles (SRM),
ivhich adhere to the inner surface of the shell
valves, is indicated. The incurrent siphonal
valve (ISV; stipled) is shown patiialbj extended
across the opening between the siphan cainty
and the mantle cavity. The incmrent siphonal
valve is attached to the lateral walls of the in-
current siphon and to the septum between the
incurrent and excurrent siphons.

siphon leading to the mantle cavity (a
detailed report of the electrophysiological
properties of the muscle fibers will appear
separately; Prior, 1974). This valve is attached
to the base of the muscular wall separating the
two siphonal cavities and to the lateral walls of
the incurrent siphon cavity (Fig. 1). The valve
protrudes across (partially occluding) the inner
incurrent siphon opening. The incurrent
siphonal valve is composed of two bundles of
smooth mu.scle fibers and a diffuse array of
muscle fibei-s sandwiched between two layers of
epithelium (Fig. 2).

The activity of the incurrent siphonal valve
was examined by removing from the animal the
entire siphonal apparatus (mantle musculature,
siphon retractor muscles and intact visceral
ganglion) to a wa.x dish of cold (10° C) sea
water. With this sort of arrangement the ten-
tacles and inner walls of the siphons could be

FIG. 2. This is an illustration of the incinrent
siphonal valve (ISV) as seen by looking into the
t'xttnial ixj)ening of the incurrent siphon (see
arrow in Figure 1.}. The ISV (stipled area) is
composed of a pair of distinct valve muscle
bundles (VMB) and diffuse muscle fibers that
are spread throughout the valve sandwiched
between two epithelial layeis.

tactily stimulated while observations were being
made on the activity of the siphonal valve.

In response to gentle tactile stimulation of
siphonal tentacles the dispersed muscle fibei-s of
the valve contract, resulting in extension of the
flap across the incurrent siphon cavity. This
movement of the valve effectively separates the
incurrent siphon cavity from the mantle
cavity.

In response to stronger tactile stimulation
(e.g. poking the siphon wall with a stylus) the
paired muscle bundles of the valve contract in
synchrony. The contraction of these muscle bun-
dles causes withdrawal of the valve; thus
opening the passage between the siphon and
mantle cavities.

It is interesting to note that in the intact
animal, the cleaning reflex requires contraction
of the incurrent siphonal valve to allow egress
of the jet of water from the mantle cavity.
Equally pertinent is the fact that the neurons
controlling the posterior adductor muscle (the
contraction of which is involved in the ex-
pulsion of water from the mantle cavity) are
activated only by strong tactile stimulation
(Mellon. 1967; Mellon and Prior, 1970). The

Vol. 88 (4)

THE NAUTILUS

117

activity of these motoneurons (hence the
posterior adductor muscle) is inhibited by weak
tactile stimulation of the siphons. Therefore,
a correlation exists between the responses
of the motoneurons that activate the adductor
muscle (involved in the explusion of water
in the cleaning response) and the responses
of the siphonal valve muscle which must be
open to allow the exit of water.

The responses of the incurrent siphonal valve
are in concert with the responses of the adductor
muscle, both contracting in response to strong
tactile stimulation.

On the basis of the foregoing observations,
I suggest that the incurrent siphonal valve might
temporarily entrap sand particles, thus pre-
venting their entrance into the mantle cavity.

The siphonal valve could respond to sand
grains falling on the siphons (presumably a weak
tactile stimulus) by extending across the incur-
rent siphon cavity, entrapping the sand within
the cavity. A subsequent contraction of the
adductor muscles, synchronized with contraction
(opening) of the siphonal valve muscle bundles,
would expel a jet of water and the previously
entrapped sand; the cleaning reflex.

Thus, the incurrent siphonal valve seems well
suited for mediation of the "sand storage" sug-
gested by Jacobson on the basis of behavioral
observations.

A portion of this study was done at the Marine
Biological Laboratory, Woods Hole, Massa-
chusetts. This work was supported by NIH
Biomedical Sciences Support Grant 5 S()5
RRO7114-06 to the University of Kentucky and
a Grass Foundation Fellowship in Neuro-
physiology.

LITERATURE CITED

Jacobson, M. K., 1972. Observations on the
Siphonal Behavior of Young Surf Clams,
Spisula Solidissima. The Nautilus 86 (l):25-26.

Mellon, DeF., 1%7. Analysis of Compound Post-
synaptic Potentials in the Central Nervous
System of the Surf Clam. Jour. Gen. Physiol.
50 (3):759-778.

Mellon, DeF. and Prior, D. J., 1970. Comixjnents
of a Response Programme Involving Inhibitory
and Excitatory Reflexes in the Surf Clam.
Jour. Exp. Biol. 53:711-725.

Prior, D. J., 1972. Electrophysiological Analysis
of Peripheral Neurons and Their Possible
Role in the Local Reflexes of a Mollusc.
Jour. Exp. Biol. 57: 133-145.

Prior, D. J., 1972. A Neural Correlate of Stimulus
Intensity Discrimination in a Mollua-. Jour.
Exp. Biol. 57:147-160.

Prior, D. J., 1974. An Analysis of Electro-
physiological Properties of the Incurrent
Siphonal Valve Muscle of the Surf Clam.
Spisula solidissima (in press).

BOOK REVIEW

OYSTERS (TREATISE ON INVERTEBRATE
PALEONTOLOGY). By H. B. Stenzel. 1971.
Part N, Bivalvia, vol. 3. pp. 953-1221 153 pis.
in text. Geological Society of America. P. 0.
Box 1719. Boulder. Colo. 80302.

This excellent and well-illustrated systematic
treatment of the subfamily Ostreina appeared
three years ago but is still deserving of a re-
view. Nearly half of the volume is a splendid
treatment of the anatomy, distribution, ecology
and phylogeny of the oysters. New genera and

subgenera are proposed, including Hyotissa
for Mytilus hyotis Linne, and Neopycnodonte
for Ostrea cochlear Poli. Our Caribbean Coon
Oyster, formerly Ostrea frons Linne, is now in
the genus Lopha Roding and the subfamily
Lophinae. The volume contains an index and
errata and revisions to the earlier two bivalve
volumes 1 and 2 of Part N.

R. Tucker Abbott
Delaware Mvseum of Natural History

118 THE NAUTILUS October 25, 1974 Vol. 88 (4)

SECOND LOCALITY RECORD FOR MESODON LEATHER WOODI PRATT

Donald W. Kaufman

Department of Zoologj-, University of Texas
Austin, Texas 78712

Mesodnn leatheru'oodi Pratt was recently
described from specimens collected at a single
locality in western Travis County, Texas (Pratt,
1971). It is of interest to report the occurrence
of M. leatherwoodi in the Pedernales Falls
State Park, Blanco County, Texas which is
approximately 13 miles upstream from the type
locality. Four specimens were found near the
Pedernales Falls within 1 m of each other at
the base of a large rock on August 6, 1972. The
collection site was above flood debris along the
river suggesting that the snails were from the
general area of the Falls, although, the shells

may have been washed down from the oak-
juniper community higher on the river bank.

The specimens have been deposited in the
collection of the Foil Worth Museum of Science
and History (catalog number 94V-3101). W. L.
Pratt verified the identification of the
specimens.

LITERATURE CITED
Pratt, W. Lloyd. 1971. Mesodon leathenvoodi
a new land snail from central Texas. The
Veliger 13 (4): 342-343; 1 pi.

INDO-PACIFIC
MOLLUSCA

MONOGRAPHS OF THE MARINE MOLLUSKS OF

THE WORLD WITH EMPHASIS ON THOSE OF

THE TROPICAL WESTERN PACIFIC

AND INDIAN OCEANS

The most technical and most beautifully illustrated
jdurnal now being published on Recent and Tertiary marine
mollusks. Over 20 professional malacologists are currently
contributing. Edited by R. Tucker Abbott. Among the
groups treated are Strom bidae, Cassidae, Tridacnidae, Tur-
ridae. Littorinidae. Phasianellidae, Patellidae, Harpidae,
and soon to come. Mitridae.

\?suc<\ to date in l(Hiseleaf form with three sturdy, perm-
anent binders — ]'M> pages, S)i)7 plates (4.3 in full color).
Limited number of complete sets left. $10.5.90 U.S. (foreign:
.$108.00), postage paid. Any numbers of extra binders
available at $6.00.

Published by
The Delaware Museum of Natural History, Box 3937, Greenville, Delaware 19807 U.S.A.

Vol. 88 (4)

THE NAUTILUS

119

DEATH NOTICE

We regret to announce the death of John
Quincy Burch, at Seal Beach, California, on
August 7, 1974, at age 80. An obituary is
planned for a future number of The Nautilus.
Further information is found on page 220 of
American Malacologists.

NEWS

Research on an index patterned after C. D.
Sherborn's INDEX ANIMALIUM is underway
at the National Museum of Natural History,
Washington, D. C. 20560, U.S.A. The coverage
is Mollusca only, and plans are to include
original references for names of species and
subsequent references to publications including
illustrations. The period of chronological
coverage begins in 1850, where Sherborn ended,
and continues through 1870 to provide an over-
lap with the ZOOLOGICAL RECORD.

Persons having knowledge of or access to
obscure pertinent references are invited to
correspond with the compiler, Florence A.
Ruhoff, Department of Invertebrate Zoology,
Mo Husks.

American Malacologists has proved to be very

useful and interesting book for all those who

correspond with other collectors or those who
do research on the history of malacology.

american malacologists

EDITOR-IN-CHIEF
R. Tucker Abbott
duPont Chair ol
Malacology,
Delaware Museum
ol Natural History

a national register of living
professional and amateur
conchologists

$12.50

plus biographies of 500 great,

as well as little-known,

American malacologists of the past

American Malacologists

P.O. Box 4208
Greenville, DE 19807

AMERICAN MALCOLOGISTS
1975 Supplement

The managing editorship and main office of
the national register of amateur and professional
malacologists have now been entirely trans-
ferred to Dr. R. Tucker Abbott, P. 0. Box
4208, Greenville, Delaware, 19807. All cor-
respondence, listings, and orders should be
sent to the new address.

A supplement for 1975 is now being prepared
and will be ready for mailing in early spring.
The cost will be only $1.00, and it will con-
tain address changes and a listing of the
names, address and interests of new registrants.
A special discount of 20% is now offered on
the purchase of the 1974 hardbound, 494-page
volume to those who send in for a free appli-
cation form. The new reduced price is $10.00,
plus 50 cents for postage and handling.

Price Reduced:

LIVING VOLUTES

A Monograph of the Recent Volutidae

of the World

by Weaver and duPont

A classic identification book with
375 pages and 79 full-color plates. Form-
erly $55.00, now only $36.00, plus post-
age (25 cents in the U.S.). Order now from
your local bookdealer or:

Delaware Museum of Natural History
Box 3937, Greenville, DE. 19807, U.S.A.

120 THE NAUTHA.-

October 25, 1974

Vol. 88 (4)

INTRODUCING MOLLUSKS

By G. Alan Solem,

Field Museum of Natural History, Chicago

An excellent introduction for both tfie amateur and
professional, this book provides wide-ranging in-
formation on mollusks and their probable patterns
of evolution. It not only relates the major ecological
shifts and structural adaptations of mollusks. but
also explores the basic living problems faced in
colonizing a new region and tells how they were
solved by different molluscan groups.

Writing from a rich background in the field of mol-
lusks and their shells, the author sets forth new
ideas about what the first mollusk might have
looked like and why it eventually had a spiral
shell. He further speculates on the origin of
snails, why pulmonate snails are so successful on
land, and why so many land snails evolved toward
slugdom.

Profusely illustrated with unique and attractive
drawings and photographs, this volume will be
welcomed by anyone interested in the evolution,
ecology, and diversity of mollusks.

1974 289 pages $9.95

Available at your bookstore or from Dept. 358

WILEY- INTERSCIENCE

a division of John Wiley & Sons

605 Third Avenue

New York, N.Y. 10016

In Canada: 22 Worcester Road. Rexdale. Ontario

Price subject to change without notice

092 A4779-WI

BOOK REVIEW

THE SHELL MAKERS - Introducing
Mollusks By G. Alan Salem, rii + 289 pp..
1-36 figures (1^2 in color). 197U. John Wiley
and Sons, Inc., 605 Third Avenue, New York,
N. Y. 10016. Hardback, $9.95.

There has long been a need for a good ac-
count of the evolutionary development of the
Mollusca, and this book adequately fills that
niche. There is a refreshingly large amount
of information new to the zoological reader,
much of which is illustrated by excellent
drawings. The author is probably the world's
leading expert on land mollusca and has the
distinction of having pioneered in the use of
the scanning electron microscope for
studying mollusks.

The photographs and interpretations of the
ultra-microscopic features of the radulae and
shell sculpturing are significant advances in
the field of mollusks. Other valuable parts of
the book contain an account of the evolution
of the shell-less pulmonates and a discussion
of the adaptive thresholds in the development
of the various classes of mollusks.

The book is well-written and not without
humor. Some of the chapter headings are
"On Becoming Sluggish", "The Slow and the
Quick" (referring to chitons and cephalopods),
and "To Scrape a Living." I heartily recom-
mend this book, not only as background (and
"foreground") reading for college courses in
malacology and evolutionary biology, but
also to amateur conchologists who admire shell
makers.

R. Tucker Abhutt

duPont Chair of Mdltwoloyy

Delaware Museum of Natural Hiiitory

INFORMATION FOR SUBSCRIBERS

Back issues from volume 72 to date are

CONTRIBUTORS

the printer may set them in 8 pt. type. There is a
charge of 50 cents per word for this extra service. All
authors or their institutions will be charged 50 cents
per line of tabular material and taxonomic keys. The
publishers reserve the right, seldom exercised, to
charge $32 per printed page.

An abstract should accompany each paper.

MOLLUSK VOUCHER SPECIMENS

It is becoming increasingly important for future
research purposes that an identified sampling of
species mentioned in pubUcations be deposited in
a permanent, accessible museum speciaUzing in
mollusks. This is particularly true of mollusks used
in physiological, medical, parasitologjcal, ecological,
and experimental projects.

The Delaware Museum of Natural History has

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